President Ronald Reagan's inaugural committee was accused yesterday by Sen. William Proxmire (D-Wis.) of sticking taxpayers with at least $4 million in "hidden inaugural expenses" -- including $1.8 million for around-the-clock military chauffeurs for dozens of Reagan's friends and his personal housekeeper.

Inaugural cochairman Chairman Charles Wick called Proxmire's charges "unfair and beneath the dignity of a U.S. senator."

According to Proxmire, the committee used 1,120 military officers -- mostly majors -- as chauffeurs during last month's four-day inauguration which was the most expensive in the nation's history.

Citing records he obtained from the Army, Proxmire said drivers and military escorts were assigned on Inauguration Day to 274 celebrities plus Reagan's personal guests: Evangelist Billy Graham, Mrs. Nelson A. Rockefeller, former treasury secretary John B. Connally, civil rights leader Ralph Abernathy and former secretary of state Henry A. Kissinger. None had any official role in the inauguration.

Some drivers had been assigned to the committee since November, Proxmire said, providing 24-hour service to 70 top inaugural officials.

During the inauguration, drivers, cars and escorts were provided to 42 entertainers, 48 governors, D.C. Mayor Marion Barry, all of Reagan's Cabinet members, eight congressmen, Chief Justice Warren Burger, Gen. Omar Bradley and about 60 honored guests including Reagan's housekeeper.

The committee received 456 cars free from American automakers for use during the inauguration.Gasoline also was supplied free by American oil companies.

Proxmire gave the committee his monthly Golden Fleece award for the biggest and most ridiculous waste of government money in January.

"While the new administration was preaching the need for austerity in government, its presidential inaugural committee was practicing conspicuous comsumption," charged Proxmire, who said Reagan's committee had intentionally misled the public by claiming that tickets to inaugural events, memorabilia sales and private contributions paid for the $8 million-plus inauguration.

Proxmire said the committee is concealing "hidden public expenses" including $1.3 million allocated by Congress to the District to help pay for extra police and city services, $463,00 spent by Congress for Reagan's swearing-in ceremony on the West Front of the Capitol and $661,000 allocated to the General Services Administration for office space, materials and employe overtime for inaugural expenses.

Another hidden expense, Proxmire said, is the tax deduction contributors to a special trust fund will receive.

Wick accused Proxmire of "misconstruing the facts." The government always has allocated money to the District and the GSA for inaugural expenses, and Congress has always paid for the swearing-in ceremony, he said. Traditionally, the military has provided drivers to the committee, Wick said. In 1977, President Carter not only used military drivers but military vehicles and gasoline, Wick said.

Frank Sinatra and other entertainers performed free, Wick said, and free drivers were a courtesy for their participation. Wick said inaugural volunteers like him and his wife deserved free chauffeurs because they worked long hours without pay. Dignitaries like Kissinger, he said, deserved the service out of courtesy.

"I don't think having a driver for the entertainers or for the volunteers on our committee is an unjust expense."

Wick also said he did not think it was improper for the committee to provide an escort and driver to the Reagans' housekeeper. "This is a wonderful woman who has worked for the Reagans 22 years," he said. "We wanted her here."