I'm not sure I get it right what you want to achieve,
but you are probably looking for JAXWS handlers.
I also recommend you to read the following spec. before you will start to code anything:
Thank you for your answer.
Unfortunatly I dont think that i can work with handlers as they have to be registrated in the services. (This is how i understand it, please tell me if my understanding is wrong)
I need to extend a incoming/outgoing message and I am not allowed to configure anything in the webservices. It should be a kind of a Filter/Intercepter which takes away/adds an id to the soap request/response before/after they reach the services. I also thought of a proxy but this doesnt work because of my further tasks.