Madison police are looking for a 41-year-old man who forced a woman to drive to an A-T-M and withdraw cash for him.  The woman says Marvin M. Baker told her he had a gun while he was getting into her car shortly before noon Monday.  She was stopped at a stop sign at the time.  The 22-year-old woman says Baker left her unharmed near Olbrich Botanical Gardens after she handed over some cash, then he drove away in her car.