An automated activity calling a web service

Hi,

I am on SAP NetWeaver 7.2 SP0. I have one automated activity which is calling a web service in a seperate lane. Automated activity has a access to service interface but I want to go to the finer level of granularity. I have attached security policies to wsdl and further want to secure soap message. I wonder how can I have access to wsdl policy assertions and soap message in code?

thanks in advance