The FOR XML clause is to generate the schema needed by BizTalk to call the procedure. All the schema has in it is, what to call, what type it is, what to send and what to expect back. After that, it literally makes a TSQL call to the DB.
if you cant (or dont want to) write the schema up yourself, go to that stored proc and generate a script for it that will allow you to replicate it on a dev server. Add the FOR XML and XMLAUTO clauses and run your wizard against that. Finally, when you are ready to run it against production, change the connection string in the runtime properties on your admin tools and let er rip.