THE SHORTEST ROUTE through the maze of federal agencies can be found by consulting the "Roadmap Program" staff in the Commerce Department's Office of Business Liaison. Whether your interest has to do with packaging and labeling regulaltions for products or locating government procurement agents, staffers reportedly will direct you to the people with the answers and the influence. If you're in need of assistance, write Office of Business Liaison, Room 1066, U.S. Department of Commerce, Washington, DC 20230, or call (202) 377-3176. Also, try calling a Federal Information Center; there are now 41 FICs located throughout the United States.