Despite the new furor over U.N. Ambassador Andrew Young's latest press interviews, the White House managed yesterday to administer na indirect pat on the back, as well as a public slap on the wrist, to its diplomatic enfant terrible.

The reprimand was delivered by Young's boss, Secretary of State Cyrus R. Vance, in Geneva yesterday in rebuke for the ambassador's widely publicized statement on the existence of political prisoners in the United State as well as in the Soviet Union.

But the back-handed pat came in the form of a more routine but still significant announcement on the agreement reached Wednesday in Luanda, Angola, between an American-led western delegation and African guerrillas who accepted a peaceful transition to independence in the disputed territory of Namibia (Southwest Africa).

A statement released by the White House just before the president's departure for Bonn said, "The president appreciates the efforts of all the parties involved including the frontline states of Africa whose cooperation has been so essential in the important progress which has been made."

The fortuitous juxtaposition of the frown and the smile underscore the delicate handling that the Carter administration is now according to its diplomatic "point man," who could previously count on White House supin the frequent flaps that have developed over his freewheeling verbal style.

After several months of a much more somber mood in American-Soviet relations and an intense debate in the administration over dealing with the Soviets and Cubans in Africa, Young's outspokenness now evidently falls on for more sensitive ears in Washington.

This is happening exactly as Young's policy of wooing the more militant "frontline states" that border on Namibia and Rhodesia, in hopes they would bring the guerrillas into meaningful negotiations with the ruling white regimes, is paying its first important dividends.

White national security affairs adviser Zbigniew Brzezinski and CIA Director Stansfield Turner sought confrontation with the Angolan government after the May invasion of Zaire's Shaba Province, Young sought more cooperation with Luanda.

Midlevel U.S. officials aware of the details of the Namibia negotiation said yesterday that Young's "success in changing the atmosphere and restoring U.S. credibility in Africa made this breakthrough possible. Angola's attitude was absolutely essential to getting agreement on Namibia."

It was Young's influence on the militant states pushing for severe reprisals against South Africa that led to the Security Council entrusting five western nations with the task of negotiating the Namibia agreement with the Southwest Africa Peoples Organization (SWAPO), in this official's view.

Young has also been praised by moderate, pro-western leaders in the Ivory Coast, Liberia, Senegal and other countries in recent interviews. These leaders say that Young's outspoken support for black nationalism has made it easier for them to support American positions across a broad range of issues.

The ambassador managed even to turn away the wrath of Avital Scharansky, the wife of the prominent Soviet dissident on trial in Moscow. Mrs Scharansky, who had initially expressed puzzlement about Young's remarks, met with him twice in Geneva yesterday and reported later that Young had called her husband "an international hero." She appeared to be satisfied with his explanation.

But by verbally plunging into the thicket of the American-Soviet dispute over human rights at the time of the new arms negtiations in Geneva an the trials of Soviet dissidents, Young has effectively eclipsed the work he has done in Africa for the moment and elevated himself to the position of being a symbol in the increasingly bitter tugging in Washington over the fate of detente.

"Andy Young is not a foreign policy issue around here today," one Senate staffer who works for a Republican moderate said yesterday. "He is purely domestic. People have been calling in all morning, or even coming by, to say they are outraged. Nobody up here is interested in looking at progress in Namibia. Lots of people have been holding back waiting to get at him, and they feel he is vulnerable after this."

With the president and most of his senior aides in Europe, there was no authoritative political damage assessment available from the White House. But the controversy triggered a strong defense of Young by his supporters in the black community, and reminders from them that Young is a double-edged sword at home as well as abroad.

"If President Carter wants to throw away his fast-diminishing chance of reelection, all he has to do is to fire Andy Young," said Rep. John Conyers (D-Mich.). "And still dares to bring freshness and candor to a diplomatic post. He is keeping alive the new politics Carter campaigned on and was elected on."

Rep. Parren Mitchell (D-Md.) agreed with Conyers that Young's description of jailed civil rights activists and others as American political prisoners would be seen as "accurate" by most in the black community. "Andy has not hurt himself at all in the black community. And the black community is the one source of strength in the ratings for Carter tha shows up in all the polls."

Outside the black community, however, some strong supporters of Young's policy role viewed the uproar created by his remarks with dismay.

"I suppose we are in for another period of quiet from Andy and this will blow over," said one administration official. "But the sad thing is that at first everybody was saying that Andy Young would someday become the first black secretary of state. Today, nobody is saying that."