Here is how we do that in our custom PAM flows:
- have Catalog call a PAM SRF, passing some parameters, most importantly the request id
- the process behind that SRF uses web service calls to get what you need
- one web service call to login into Service Catalog
- one to get all form elements (getRequestItems)
- one to get the general info from the request (getRequestHeader - get the requested for etc fields)
- build a loop that for each form returned by getRequestItems goes fetch the form fields and their values (using getFormRateItemValues)
Then additional web service calls (this time to Service Desk) create the change order:
- login
- doSelect web service calls and XML extraction operators to get the necessary data (e.g. requested for persistent id, category, etc)
- createChangeOrder to make the ticket
An extra call to link the Catalog request to the Service Desk ticket (web service call to Catalog)
- addTicketToRequestItem
Log out from both Catalog and Service Desk.
That's the basic calls you'll need to cover I think.
Hope this helps!