Ronald Reagan should appoint regulators who are "sympathetic" with the aims of their agencies but at the same time believe there is a need to reduce the burdens their agencies impose on business, the head of the president-elect's task force on regulation said yesterday.

The lead-off speaker at a symposium on regulatory reform sponsored by the American Enterprise Institute was Murray L. Weidenbaum, director of the Study of American Business at Washington University in St. Louis. oWeidenbaum said that appointees shouldn't be "true believers or those out of sympathy" with the social goals of their agencies. They should be men and women who appreciate the social objectives to be achieved by the agency but who are equally concerned with minimizing the costs and intrusions of regulation, he added.

The power of appointment is one of three important powers available to reform government regulation, along with the legislative power and administrative power, Weidenbaum said.

New legislation cannot be overlooked, he continued. "So many problems stem from the statutes themselves." Among other things, Weidenbaum called for the abolition of President Carter's Regulatory Council, which Weidenbaum called "a protective association for the regulators."

Weidenbaum, a former assistant secretary of the Treasury, was one of nine regulatory experts yesterday to offer "advice for the president-elect," the theme of AEI's symposium at its annual "public policy week." Although Weidenbaum and the others said they were speaking for themselves, many of them already have offered the president-elect advice in other forms. Five were members of a regulatory task force; three of them also serve on a variety of working transition teams.

Among yesterday's recommendations:

James C. Miller III, calling the Occupational Safety and Health Administration "the worst-performing major regulatory agency," said some important changes can be made within the existing statute to make the OSHA a more "useful" agency. For one, personal protection devices such as earplugs or face masks should be considered acceptable substitutes to meet performance standards, he said.

Also, a directive should be issued requiring that the anticipated benefits of any new regulatory proposals exceed anticipated costs and that the least costly alternative must be chosen, added Miller.

Antonin Scalia, visiting professor of law at Stanford Law School, said the Federal Communications Commission has "by and large been very good in deregulating" but that the administration should back a rewrite of the Communications Act even if the result is less deregulation than the FCC would do on its own. "The notion that we can change the laws without changing the laws . . . frankly disturbs me," the former assistant attorney general said.