The pilot began a descent from 16,000 feet and was being vectored for an approach when the airplane was struck by lightning. The airplane continued to perform normally and an uneventful landing was made at the planned destination airport. The pilot noticed the airplane was damaged during a post-flight walk-around. The lightning strike caused minor damage to a propeller blade on the left engine and to the left wing flap. The right elevator was substantially damaged by the lightning strike. The pilot stated they had passed an area of convective activity and were in instrument meteorological conditions with smooth air at the time of the lightening strike.