Brice,
I saw in a very old thread something like this:
%%OperatorMessage %o
%%EndComments
%%Title: Check the Lake System Input Queue
%PS-Adobe
(FORM) run FORM
It seems like it was added before a trigger in the file. This assumes that the document is a printer-resident form that you call using a trigger. If that's the case, then maybe you could try adding the above code to your trigger, and see if you get operator messages. You could also try adding it to the document's comments and add a tilt, like you seem to be doing.
This may or may not work, however. This is custom postscript code after all, and not really a feature of our software, so this isn't something that we support. Also, every printers may behave differently. What works on one printer may not work on another. The old thread that I mentionned did not tell if the printer was also a Xerox, so I cannot guarantee that it will work.
Regards,
Raphaël Lalonde Lefebvre