A Bosnian hijacker today commandeered a Scandinavian plane with 129 passengers aboard before surrendering at day's end to Oslo police. He demanded that supply lines to Muslim areas in his troubled homeland be opened tohumanitarian aid. The hijacker took control of a Scandinavian Airlines System flight Thursday afternoon as it flew between the Norwegian towns of Bardufoss and Bodo. After 52 people were allowed off at Bodo, the plane flew 500 miles south to an Oslo airport. The hijacker claimed to have a grenade and threatened to blow up the plane if it was stormed by police. In a tape recording released to Norwegian media, he said: "We want to open humanitarian corridors on the ground ... (so) that food, electricity and water and all necessary things come into places that are under blockade . . . if there is no help to Bosnia, then there is no hope to all the world." .