Secretary of State George P. Shultz, under heavy congressional questioning, said yesterday that the Reagan administration opposes negotiations with Salvadoran guerrillas because "we're not going to be in the position of allowing somebody to shoot their way into the government."

Shultz, who testified before the House Foreign Affairs Committee, was forced into an uncharacteristically heated defense of administration policy by committee members who repeatedly made clear their distaste for the Salvadoran regime's human rights record and their concern that the administration wants only a military solution to the civil war.

He also angrily characterized as having "no foundation in fact" a Washington Post article last week reporting that Thomas O. Enders, assistant secretary of state for inter-American affairs, had suggested a two-track strategy of supporting the Salvadoran government while promoting negotiations with the guerrillas.

Shultz, who testified on behalf of the administration's $14.5 billion fiscal-1984 foreign aid request, made these other points during the wide-ranging questioning:

* President Reagan has no intention of giving up his "zero-option" arms control proposal, which would require the Soviet Union to dismantle all of its intermediate-range nuclear missiles in Europe in exchange for the United States not deploying similar missiles on the continent.

* Syrian Foreign Minister Abdul Halim Khaddam has assured Shultz personally that Syria will pull its troops out of Lebanon when Israeli forces leave.

* The next step in the Middle East hinges on whether Jordan's King Hussein decides to join a broadened peace process. While acknowledging that Hussein is undecided, Shultz said the king "has spoken to us very favorably about the president's initiative" and the United States is "optimistic" about the chances of Jordanian participation.

But it was the continuing controversy about El Salvador that produced the most heated exchanges. Many were prompted by the Post article, and Shultz sought to dismiss it by saying:

"The burden of the newspaper story, and what I've sought to correct, was that somehow the U.S. government has decided that what we needed now was to encourage a negotiation between the guerrillas and the government of El Salvador to bring the guerrillas somehow into the government. That approach we reject. That is not correct."

However, his description was at variance with the points made in the Post article published last Thursday.

The article noted the administration's standing policy of opposing negotiations to give the guerrillas a share of governmental power and said that the idea of exploring negotiations was being discussed "in an unspecified way."

It also said the Enders suggestion was contained in "a working paper" that had not been considered formally for adoption as official policy and stressed that the idea faced heavy opposition from some senior administration policy makers.

Several administration officials closely involved with Central American policy subsequently confirmed privately that the main details of the Post article were correct, and added that the Enders suggestion was aimed at deflecting growing congressional opposition that the State Department says it fears could block the administration's requests for hefty increases in military aid to El Salvador.

Some sources, making a technical distinction, have said that the Enders proposal called for negotiations not with the guerrillas directly but with leftist Salvadoran politicians who are allied with the guerrillas and who form the political arm of the anti-government insurgent movement.

The idea, according to these sources, was that through talks with the political figures, who are in exile, the guerrillas might be induced to lay down their arms and seek to win their aims through peaceful means.

That idea has been explored several times in the past by groups sympathetic to the Salvadoran left, but the politicians have always rejected such overtures.

Shultz hinted that such an idea has been under consideration when he said that the United States favors a "process of reconciliation" that would persuade the guerrillas to give up their struggle.

But as for dealing with the guerrillas in a way that could give them a share of power, Shultz appeared at times to echo the tough, anticommunist rhetoric associated with his predecessor, Alexander M. Haig Jr.

"Let them shoot their way into the government? No dice," Shultz said. "The guerrillas are busy upsetting people in El Salvador, creating hell, shooting their way around. They are responsible for the level of violence there. If they want to take part in a responsible way, they are welcome to do so."