emacs inject a prolog to print jobs?

[Urs Rau (UK)]

I am using the latest emacs under Mac OS X 10.6.x and would like to
print emacs buffers to a xerox printer that needs accounting codes
sent as a prolog to the print job.

Pretty sure I am not the first one that needs to do that, any hints or
links to a solution for this? How does one combine postscript files ?

Mac OS X uses, (or can use) lpr for printing, so maybe that would be
the easiest to get working?

The xerox accounting "prolog" looks something like this :


%-12345X@PJL JOB NAME = "new  2"
@PJL ENTER LANGUAGE = POSTSCRIPT
%!PS
%%XRXbegin
%%OID_ATT_JOB_OWNER "user1"
%%OID_ATT_JOB_NAME "new  2"
%%OID_ATT_JOB_TYPE OID_VAL_JOB_TYPE_PRINT;
%%OID_ATT_PROCESS_GRAYSCALE_GRAPHICS_ENABLED TRUE;
%%OID_ATT_CONTENT_ORIENTATION OID_VAL_CONTENT_ORIENTATION_PORTRAIT;
%%OID_ATT_START_SHEET OID_VAL_JOB_SHEET_FULL;
%%OID_ATT_ACCOUNTING_INFORMATION_AVP "XRX_USERID,usr";

%%OID_ATT_COLOR_MODE OID_VAL_COLOR_MODE_AUTOMATIC;

%%XRXend

The actual accouting line that makes all the difference is:
%%OID_ATT_ACCOUNTING_INFORMATION_AVP "XRX_USERID,usr";

How does one construct such a postscript filtering pipe to allow
printing form emacs?

Thanks for any pointers.

-- 
Urs Rau