WHEN I WAS in Moscow recently with a congressional delegation, our party spent a great deal of time trying, unsuccessfully, to persuade officials that we should see General Secretary Mikhail Gorbachev. Ronald Reagan won't have to do that in Geneva. Gorbachev will be sitting across the table from him, a prospect that does not seem to make our president particularly happy.

But I can tell him, from my brief exposure to the party line, what he may be hearing in these next few days, although Gorbachev may have refined the rhetoric a bit.

The setting, of course, will be quite different. We went to Kremlin offices that were, except for the inevitable portrait of Lenin, rather like bourgeois living rooms or even convent parlors. The floors and furniture were highly polished. There were white lawn curtains at the windows. At the long tables where we sat were little islands of refreshment, mineral water, fruit juice, Pepsi-Cola and jars of mints or candy.

I am sure that Reagan and Gorbachev will be in a more opulent interior, thickly carpeted, heavily chandeliered and with brocade walls that, in a diplomatic capital, have absorbed so many lies that it's a wonder they are still standing.

The dialogue, however, could be similar, if Reagan makes good on his promise to bring up shortcomings in the Soviet system. When he mentions human rights, he will be told that a job is a human right and that, whereas in the Soviet Union everyone is employed, America's jobless rate is at 7 percent. He will also be told about the human right to shelter and be given a taste of Soviet outrage about homeless Americans sleeping in the streets.

For this issue, too, the president should bone up on the case of Leonard Peltier, the Indian activist convicted of murdering two FBI agents in 1975. His attempts to win a reversal are front-page news in Pravda, getting as much space as a factory that has exceeded its production quota.

The president may also be told about a case in Woodside, Calif., which could baffle him. A stony-faced Soviet from the Stalin era told us heatedly of "a female, the mother of seven who was imprisoned for 18 years, after being accused of touching a Minuteman missile." We had never heard of her.

The matter of Andrei Sakharov, the great exiled scientist, may consume a great deal of time between the leaders. We heard several explanations about his fate. Since Sakharov's wife, Yelena Bonner, is now free to travel abroad for medical treatment and may end up being the sole sure beneficiary of the summit, Gorbachev may be less defensive about the case than our interlocutors.

A deputy member of the Politburo told us indignantly that Sakharov is lucky to be in exile in Gorki and undeservedly well off.

"He receives his pay from the Soviet Academy of Sciences. We know that Sakharov, through his wife, established relations with American intelligence personnel and American agents. Soviet power has been quite merciful to him. If it were anyone else, he would be tried for treason," he said.

"It is easy to be interested in the fate of one individual," he said, showing how the president should be at all times prepared for a rapid shift of gears by the other driver. "We are interested in the fate of millions and millions of people in the world. That is why the American press blows up the question of Sakharov, to complicate the relations between the U.S. and the U.S.S.R."

E.I. Velikhov, the vice president of the Soviet Academy of Sciences and by far the most savvy and least polemical of the officials we met, had a less heated explanation, one that seemed more plausible at the time: "It is because he came out in favor of more MX missiles. He advocated a weapon that could be used against us."

But later, in the cramped living room of a refusenik, that was refuted. One of the harassed Soviet Jews said to us, "That is a lie. He was still free after he came out for the MX. It was after he opposed the invasion of Afghanistan."

Maybe Gorbachev will level with Reagan about Sakharov and confirm the obvious, that the Soviets just can't stand dissidents.

He will also hear about Jewish emigration. We were told that Jews are comfortable in Soviet Russia -- although that sounded fishy because no one else seems to be -- and don't want to leave.

Georgi Arbatov, the Kremlin's top Americanologist, gave us a more unvarnished view. If we let the Jews go, other minorities would think that they were free to emigrate, too, he suggested. Under those conditions, he hinted, the Soviet Union could be rather promptly depopulated.

As I see it, the only way they will get anywhere is to start talking about arms control. All other subjects lead to dead end, as far as we could tell.