PB 6.0: How to change the printer's setup ?

I would like to change the printer's setup by the programming
in PowerBuilder 6.0 (HP LaserJet 1000)

I have found the "PrintSend" function in help:
"PrintSend" sends an arbitrary string of characters to the printer.
"PrintSend" is usually used for sending escape sequences that change the printer's setup.
But Escape Sequences are printer specific... (Oops !)

In reality, I would like to change the default orientation of paper to landscape.

Example:
--------

Long Job

Job = PrintOpen()      //Open a print job
PrintSend(Job,"???")      //Send an escape sequence
...
PrintClose(Job)            //Send the job to the printer or spooler

Thanks in advance, Cedric (:=D