Place hot dog on a microwave-safe plate and heat on High until warm, about 30 seconds. Place tortilla on a microwave-safe plate, and heat on High until warm, about 15 seconds. Lightly spread the tortilla with margarine. Place the cheese slice on the tortilla, and top with the hot dog. Fold the ends of the tortilla in over the hot dog and roll to close. Heat the tortilla dog in microwave on High until cheese melts, about 30 more seconds.