The anti-inflation game moved to Capitol Hill yesterday as nearly half the Senate signed up in support of a resolution to cut spending next year as much a $35 billion below what the president has proposed, and limit it in the future to a set percentage of the gross national product.

Some of the 43 senators, including William V. Roth (R-Del.), one of their leaders, said they would filibuster if necessary to force their proposal to a vote on the Senate floor in the coming days.

Assorted proposals to hold future spending to set percentages of gross national product are under consideration in the House as well, and this is one of the options a White House task force is discussing in a review of administration economic policies begun last Sunday.

As the senators held a news conference on their proposals, a House Budget Committee task force moved on another front also under White House study. It asked President Carter to name a group of economists to suggest a new way to compute the consumer price index.

By law a large part of the budget -- such items as Social Security benefits, for example -- rise automatically each year with the CPI. But the group says the index exaggerates inflation because of the way housing costs are treated. As a result, they claim, the government next year will pay up to $7 billion more than it really should in cost-of-living adjustments in these programs.

Roth and 42 other senators introduced a resolution directing the Budget Committee to hold spending in the 1981 budget to 21 percent of GNP. Carter proposed spending $615.8 billion, 22.3 percent of what the administration estimates GNP -- the total value of all goods and services produced in the nation -- will be in 1981.

But there were few suggestions for specific program cuts, prompting Senate Budget Committee Chairman Edmund S. Muskie (D-Maine) to question wryly whether the budget-cutting fervor would pass the test of roll-call votes on popular programs.

"My enthusiasm . . . is tempered by some fundamental misgivings," Muskie said noting that most of the senators backing the spending limit had voted just a month ago for budget-bursting increases in veterans' benefits and Social Security disability payments.

In contrast to a $35 billion cut, the administration task force reportedly is contemplating trimming spending by about $10 billion for 1980 and 1981 combined.

A further dash of cold water was thrown on proposals as ambitious as Roth's by Rep. Paul Simon (D-Ill.), a member of the House Budget Committee. He noted that the Congressional Budget Office thinks Carter underestimated likely spending next fiscal year by about $15 billion. That would make it all the harder to get the total back where Roth and the other senators say they want it.

Both, however, promised his resolution's supporters would "debate until the Senate takes bold and decisive actions of inflation. Let the Congress lead the way for a change," he told reporters.

Decisiveness seemed to fade, however, when reporters asked Roth and his allies where they would make their cuts. Roth said only that he would have a detailed list sometime soon.

When Sen. William Proxmire (D-Wis.) said his spending hit list included "fat" in the defense budget, reporters asked others in the group if they, too, advocated cuts in military spending. Sen. Peter V. Domenici (R-N.M.) replied, "Absolutely not."

Roth said he thought Congress could increase defense spending while cutting the budget as a whole and even reducing taxes.

Muskie later praised Roth's proposal as "serious and very important" but added sardonically, "It is encouraging to see that so many of these senators who refused to pay the price for fiscal discipline just one month ago are now eager to make public demands to end such profligacy. One can only hope that in the future there will be a closer relationship between roll-call votes and lists of co-sponsorship on the issue of fiscal discipline." r

According to Muskie, 34 of the cosponsors voted last month to exceed the congressional budget target for veterans' programs by $350 million in 1981 and $417 million in 1982. Twenty-six did the same on disability insurance, boosting it $132 million over its budget limit for 1981, he said. Roth himself voted against these spending increases.

Meanwhile, the Senate Finance Committee offered another prescription for spending discipline that also came from Roth but took a different tack. With Chairman Russell B. Long (D-La.) going along, but noting the absence of liberal members and reserving the right to reconsider, the committee agreed that any revenues raised in excess of $600 billion next year should be reserved for cutting taxes or reducing the federal deficit.

The proposal, in the form of a nonbinding recommendation to the Budget Committee, would not affect Carter's proposed $15 billion in deficit spending for the year. It would only bar spending of revenues that exceed $600 billion, which is the administration's and the Finance Committee's revenue estimate for fiscal 1981.

The House and Senate Budget Committees will begin preparations next month of nonbinding budget resolutions covering revenues and outlays for the 1981 budget. In September, the resolutions will be revised and become binding on congressional actions unless explicitly waived.

Administration officials continued to meet with members of Congress seeking ideas for budget cuts or other anti-inflation measures. One of them, James McIntyre, director of the Office of Management and Budget, assured the chairman of the House and Senate Budget committees that any changes would be made through the regular budget process.

That would seem to mean the administration plans to conclude its review and make public its new proposals before the mid-March deadline for submitting the final re-estimates for the 1980 budget to the committees.