Set a string to be included in the PostScript DocSetup section.
void pdfPrintSetPSCustomDocSetup(PDFHandle pdf, char *docSetup)
This function provides a string of PostScript code to be inserted in the PostScript document setup section (%%BeginSetup .. %%EndSetup). This is useful for inserting device-specific calls to setpagedevice, etc.

This setting is only relevant for PostScript printing. It will be ignored when printing to a non-PostScript printer or if pdfPrintForceGDI is in effect.

pdfPrintSetPSCustomDocSetup(pdf, "<< .... >> setpagedevice");