On Their Way Back To France - Herve Alphand, left, permanent French representative to the U.N., and French Foreign Minister Antoine Pinay, right, are escorted by Maurice Couve de Murville, center, France's ambassador to the U.S., as they walk to plane at Idlewild Airport tonight for trip to France. The French delegation withdrew from the Genera Assembly of the United Nations following the Assembly vote to debate the Algerian issue. France's stand is that the Algeria situation is an internal matt