I'm not sure how accessible the dampner bolt is on your car, but I imagine you can get at it from underneath. It shares the same centerline axis with the crankshaft. The dampner is mounted on the nose of the crankshaft outside the block and oil pan at the front of the engine. This dampner is what powers the belt. The bolt is somewhat recessed in the dampner. It's torqued on there pretty good, so this bolt is what is usually used to turn the engine.
It just dawned on me that turning the engine may take some effort because of the accessories, but should not be impossible. If you're worried before undertaking this task, practice turning the engine with the dampner bolt before starting anything.
95 E320 Cabriolet, 131K