The lawyer trying to block extradition of Carlos Suarez Mason, a former Argentine general, on murder charges was ordered by a San Francisco federal judge to represent Suarez Mason in a $20-million civil suit by an alleged torture victim and threatened with disbarment if he refuses. Attorney J. T. Prada replied that he would have to refuse, because he has never tried a civil case and is not competent to handle this one. Ephraim Margolin, Prada's lawyer, said there is no authority under federal law to require a private lawyer to take a civil case, as opposed to criminal cases, in which lawyers are routinely appointed for the poor at government expense. But U.S. District Judge Samuel Conti said the civil case is "part and parcel" of the extradition case and Prada must take it without additional payment or find someone who will. Suarez Mason, 63, commander of the First Army Corps in Buenos Aires from 1976 to 1979, is charged with 43 murders and 24 kidnapings of civilians, allegedly committed by soldiers under his command.