Dudley,
my control chain is NetRemote 2 -> Girder 4 -> MC12. So NR is sending command to G4 and G4 to MC. To send a message to MC you must use the CommandCapture action. then fill out the following parameters:
Message: 33768 (always)
wParam: 10023 (this is the command you wish to send, in this example set rating)
lParam: 5 (parameter for the command, in this example 5)
Sendmessage/Postmessage: SENDMESSAGE
Then select the target application using the Windowpicker and fill out:
Match invisible Task: YES
Classname: MJFRAME
Executable: MEDIA CENTER 12.EXE
In my example I set the rating of a file to 5. For other commands just replace the wParam and lParam. The list of MCC_Commands can be found in the wiki. As you already read, the next version will support the loadlibrary command that makes things easy.
Cheers,
Marc