software that will take an IPDS spool file and turn it into
something that can print to an HP printer
I have not tried this, but the link sounds interesting. "Virtual IPDS Printer", "IPDS Printer Emulation", "translates IPDS directly into common printer languages", "pure software emulation solution for IPDS printing".
http://www.ipdsprinter.com/virtual-ipds-printer.html
-Nathan