Early in the Reagan administration, Ed Meese decided that there would be no special White House assistant for black affairs. The president's top policy man had a different idea. Instead of the traditional setup, including what Purlie Victorious might have called a "dep'ty for the cullud," the White House staff -- black and white -- would deal with subject areas. Blacks would have access through the same doors as everyone else: not as blacks but as constituents with specific concerns.

It was an interesting -- even progressive -- idea. But it didn't work.

When the question of tax exemptions for segregationist schools came up for consideration, there was no one to tell the president that such a move would paint him as a racist in they eyes of blacks.

There was no one around to tell him that the nominations of William Bell and the Rev. B. Sam Hart, both black, but both patently unqualified for the posts for which they were considered, would more likely dismay than reassure blacks. Indeed, top administration blacks first learned of the taxexemption proposal and the nominations after the damage had been done.

President Reagan is reported to have ordered major changes in personnel practices to prevent further such embarrassment. He is seriously considering appointing a special assistant for minority affairs.

The trouble, according to key blacks in the administration, is that while the equal-access idea was basically a good one, the word never went out to Cabinet officers and other top presidential aides that they were to change their own practices to conform with the new approach. As a result, instead of equal access, blacks were effectively left without access at all, and the president has been stung by criticisms that he is running a racist administration.

He is determined to change that image. The Los Angeles Times reported last week that Reagan is leaning toward naming a special assistant to monitor civil rights problems and to oversee the recruitment of well-qualified blacks -- "without their having to pass our litmus test on civil rights."

That is a good beginning. The insistence on recruiting blacks who buy the conservative line on matters of race and social policy tends to weed out most competent and reputable blacks. That is how the administration wound up nominating Bell, who was picked to head the huge Equal Employment Opportunity Commission though he had no administrative experience, and Hart, whose handicaps included not only his unorthodox civil rights views but also a default on a federal loan and federal tax problems, to be a member of the Civil Rights Commission.

The administration, which wants to bring more blacks into the Republican Party, finally is realizing that it can't be done by using blacks who are themselves out of touch with black America.

Nearly as important as getting the right people is the necessity of getting them in the right position. If the president does decide to name a special assistant for minority affairs, for instance, it is vital that the job involve policy as well as public relations. According to the Los Angeles Times story, the current White House thinking is that the special assistant should have "high-level authority to cut across the lines" of personnel and political affairs. That suggests that the job would be under either Michael Deaver, whose strength is public relations, or James Baker, the "process" man whose forte is getting policy implemented.

In either case, the special assistant would likely find himself working primarily as an administration apologist: explaining policy that he had no role in formulating.

What makes far more sense, assuming the president's seriousness in changing his image in black America, is to place the special assistant under Meese, the policy man. Unless he could directly influence policy, a black special assistant would be less likely to enhance the administration's credibility among blacks than to destroy his own.

The negative perception of the administration among blacks may focus on specific programs and policies, but its heart is the sense of a changing racial climate in America. As one black official put it, "The main concern of blacks is not the specifics but their general fear of racial retrogression at the hands of the Reagan administration."

You can't fix that one with PR.