Hi Colm,
report Z_PCO_AGENT_COMMANDS is described in this document http://scn.sap.com/docs/DOC-32671 (I thought you already found this document on SCN). The report also works for the socket agent we use to connect EWM MFS. It shows you the commands and the parameters of the commands you need to create your query in ABAP.
Greetings
Uwe