Hmmm, not really sure what is your use case here. Why would you like to do yourself something that is already managed by the engine (storing session and process instance information)? If you could give more requirements for it maybe I will be able to get your idea otherwise it is very difficult to follow it. Sorry German won't help me at all ;)
Unfortunately I am not an expert in the marshalling world so can't help you much with that. But maybe there is another approach to that ... :)