I don't know enough about AS400 to help much there, but IBM states this:
Xerox AltaLink and Connectkey products do that right here
And the PDL reference guide has the stuff you would need to add to a print stream to do it that way, but I have absolutely no idea how to implement that information outside of Linux with a PPD.
I read an IBM article on how to integrate accounting ID to a WSCST in AS400. (http://www-01.ibm.com/support/docview.wss?uid=nas8N1012398)
Unfortunately the PCL that I recovered was in XML. I want to integrate the WSCST including in the XTOOLS0923 that I downloaded for AS400. Please help. Thanks.