To be young, black, and making it in South Africa

As the city skyline lights up, Eric Mafuna slips on the jacket of his tailored three-piece suit, locks the door of his posh 20th-floor office, climbs into his sleek automobile, and heads for home. He is the very picture of the young executive with the world at his feet.

But Mafuna's world is about to be transformed. His drive home is a jolting reminder that he is a black in white-run South Africa. He lives in Soweto, where the air is dirty, the streets unsafe, and the neighbors suspicious of a black man who moves in the white corporate world.

There is a very small group of blacks achieving some success in South Africa's white-controlled economy. Some call this an emerging black middle class , although its small size may not justify the label ''class.''

But members of this group use terms like ''painful,'' ''frustrating,'' ''confusing,'' and ''schizophrenic'' to describe their lives. Success, for many of them, seems to heighten rather than diminish their discontent with South Africa's white minority government and its policy of apartheid.

That government has hoped a black middle class would, out of self-interest, act as something of a political ally, resisting the calls for radical and rapid change that are increasingly heard in the black community. Conversations with blacks who might fit into this class say Pretoria's hopes are not being realized.

''The black middle class is not in any way an ally of the status quo,'' says Moses Maubane, managing director of the African Bank. ''The laws of apartheid affect everyone who is black.''

Dr. Lina Human, a University of South Africa sociologist studying black mobility, says it is important to recognize first off that the number of blacks moving into nontraditional jobs is very small, albeit growing.

For instance, in 1981, blacks held less than 2 percent of all the managerial, executive, and administrative jobs in South Africa.

And for those few blacks who break through the job barriers, structured to keep blacks mainly as a laborer class, the fruits are often dubious. ''On the one hand, they are classified as blacks in apartheid society, and on the other, they are expected to function on an equal basis with whites. It's an extremely confused position,'' says Dr. Human.

South Africa's laws of strict racial separation in practice mean that blacks get the lowest standard in housing, education, and other community services. A degree of affluence can improve things at the edges for blacks. But it can never allow blacks to escape the inequities of the system.

Further, there are tremendous social pressures against a successful black ever giving the impression that he is buying his way even marginally out of the black community.

''Blacks who have made it don't want to show it because it's dangerous,'' says a black man who considers himself part of the new middle class.

Mafuna, a father of two who earlier this year started his own advertising and marketing company, called Consumer Behavior, says flatly, ''I love being part of the middle class.''

But he points out his success has made him ''possibly more bitter.'' He travels overseas, moves freely by day in South Africa's white corporate world, and can see vividly all the things denied him because of the color of his skin.

His watchful Sowetan neighbors look for signs he is ''selling out'' or growing aloof from the community. So he goes out of his way to get involved in community projects and to live in an understated manner to demonstrate this is not happening.

Elizabeth Mokotong, a university researcher, views the black middle class from the twin perspective as a member and as a past social worker in the Mamelodi township near Pretoria.

''It's not a comfortable position,'' she says. ''You don't know what most people think of you.'' Mokotong says blacks who have moved out of traditional laborer jobs tend to regard themselves as very fortunate. They realize that the vast majority of their neighbors, through no fault of their own, will not be so fortunate.

One of the most difficult choices faced by blacks who have gained some affluence is how to use it for the benefit of their children. A top priority usually is a better education, given the widespread view among blacks that the public schools administered by the white government are of poor quality and aim to indoctrinate.

However, as Mafuna notes, ''Taking black children to white schools is still resisted by the black community.'' The idea of going hat in hand to a white private school, some of which sometimes are allowed to accept blacks, is humiliating. Also, some black parents feel it will give their children a misleading picture of the society that awaits them.

Still, almost all of the successful blacks interviewed send their children to private schools outside the black townships. The most common reasons given: Parents have a responsibility to give their children the best education possible , and the black community ultimately benefits when blacks assume positions of power in South Africa.

One reason economically successful blacks apparently do not feel beholden to ''the system'' is that they do not credit their success to any change of heart by the government. South Africa's economy can no longer be run only by whites, and blacks feel some of their ranks are being allowed into nontraditional jobs simply out of necessity.

However, job mobility can have a certain ameliorating effect.

''Your natural anger is assuaged because you can see things from a less emotional stance,'' says banker Maubane. ''You don't hate the Afrikaner blindly.''

But in Maubane's experience, ''This clearer, less emotional view actually heightens your appreciation for the need for rapid change,'' in South Africa.

It is an indicator of the black community's ambivalent attitudes toward members of this so-called emerging middle class that they are not necessarily becoming role models for the young.

''In the black community the symbols of success are very much blurred. Successful types often engender an opposite emotion. The young feel you are collaborating,'' says Maubane. He adds that young blacks are ''talking socialism and increasingly view capitalism as the enemy.''

Black youth look up to those who ''can stand up and be counted'' and who ''say the right things'' politically, says a successful black.