Soap persistence on session ID

Good day,

I'm trying to configure an I rule to do Session id Persistence.

The Session ID is contained in the tag of the SOAP request and will need to be used as the persistence record.

I noticed that there are some already listed on DevCentral, however these rules use a specific session ID.

In our case the user session ID will change per user

A SID (session ID) is returned only if the access is authenticated. All subsequent web services calls need to include this SID.

Thanks