The Coalition for Consensus on Agricultural Policy holds a 9:30 a.m. briefing in Room SD-124 of the Dirksen Senate Office Building to discuss its proposals. TUESDAY Republican National Committee Chairman Frank Fahrenkopf holds an 11 a.m. news conference at the J.W. Marriott Hotel to kick off an RNC program to woo Democrats to the Republican Party. The Older Women's League holds a 10 a.m. news conference to discuss the impact of federal budget cuts on older women. The briefing will be in Room 116 of House Annex 1, 300 New Jersey Ave. SE. The National Research Council releases a report on the engineering profession at a 10 a.m. news briefing at the National Academy of Sciences. WEDNESDAY The National Conference of State Legislatures' three-day State-Federal Assembly gets under way at the Hyatt Regency Capitol Hill. The National Solid Wastes Management Association's three-day WasteExpo '85 gets under way at the Washington Convention Center. THURSDAY The National Consumers League holds a 10 a.m. news briefing at the National Press Club to discuss its efforts to persuade the Food and Drug Administration to broaden the scope of its investigation of its ban on cyclamates. FRIDAY President and Mrs. Reagan return from their trip to Western Europe.