9100 port capture

I have a frustraiting situation… I need to get a windows computer to emulate a 9100 port printer such that it can capture a print stream from a mainframe and save it as a file. (Basically I need to give the pc the ip address normally owned by the current printer and have it record what is normally printed.)

Unfortunately packet sniffing is not an option, nor is re-routing the print stream at the server end.

Does anyone have any suggestions (Short of writing my own app. )