"The president of the United States can now go to a college campus and get cheered," White House chief of staff Donald T. Regan told 1,000 business and professional leaders who gathered last night at the downtown Marriott to see him receive an award.

The distinguished service award from the Center for the Study of the Presidency, a private think tank, was for Regan himself, but like any good top kick, he seized the occasion to heap praise on his boss.

To the applause of a largely conservative gathering, Regan said the president has bolstered the economy and reestablished America's military strength. Then he turned to a subject that he said wasn't properly understood:

"The president's mind."

Regan outlined a day's work for Ronald Reagan -- briefings, meetings, politicking -- saying that "issues come at the president furiously all day." Furthermore, he said, the issues are diverse and difficult to grasp, but the president grasps them nonetheless.

"His mind is disciplined and resilient," said the chief of staff. The president is "able to give his full concentration to something," then "clear his mind" and turn to give full concentration to the next issue.

"This, then, is the Reagan mind: flexible, trained, insightful, comprehensive."

Transportation Secretary Elizabeth H. Dole, who introduced the award winner, had plenty of praise for him, calling him "a superb leader. Don has no personal agenda. His agenda is Ronald Reagan's agenda, pure and simple."

And R. Gordon Hoxie, president of the center, which is based in New York, called Regan "a truly great American" who "exemplifies . . . vigor in the executive."

It is rumored that a forthcoming book of Washington memoirs by former budget director David Stockman will deal unflatteringly with some of Regan's tactics.

Asked about this at a reception before the dinner, Regan, a U.S. Marine Corps jungle fighter in World War II, replied, "I don't think I am a tough guy . Really, I'm a softie."

Asked about former White House deputy chief of staff Michael K. Deaver, who's now making megabucks as a lobbyist, Regan said, "That's his good fortune and good luck. He worked a number of years on it. It's good to see an entrepreneurial effort work out."

Between the reception and the dinner, Regan ducked back over to the White House, a few blocks away, to be on hand for President Reagan's press conference, in which the president said of Deaver, in response to a question about his former aide's lobbying activities, "Mike has never put the arm on me."

The president also called Libyan leader Muammar Qaddafi "this mad dog of the Middle East."

Back at the dinner, Grumman Corp. Chairman John C. Beirwirth exclaimed, "Oh, that's grand!" when he heard what the president had said.

Grumman manufactures, among other things, warplanes and aluminum canoes. Beirwirth said his firm produced 70 percent of the warplanes that were on the carrier decks of the U.S. Sixth Fleet during its recent maneuvers at Qaddafi's "Line of Death" in the Gulf of Sidra area.

Beirwirth, who conversed at dinner with one of Regan's two secretaries, Brooke Vosburgh, was in a good mood because his firm cinched a $1.1 billion, eight-year contract to supply 99,150 trucks to the U.S. Postal Service.

Last night's ceremony marked the 20th anniversary of the center, which publishes a quarterly journal and holds seminars and other public policy activities.

Previous recipients of its award include Dole, Gerald R. Ford, Mamie Doud Eisenhower, William J. Casey, Edwin Meese III, David R. Gergen and Cyrus R. Vance.