CRACK MS-DOS APP TO AVOID USING A DONGLE

I use an application which works in MS-DOS. It access a parallel port dongle in order to work properly so I'd like the application to be cracked in order to avoid the dongle. If necessary I can send a dongle to the bidder to do tests. I use this APP in Linux using DOS-EMU emulator. Somebody suggested me that instead of cracking the APP some code could be written in DOS-EMU to skip the dongle, but this APP only works with one version of DOS-EMU (not the latest), so I would preffer the approach of cracking it (because it is more definitive). I would provide the full directory tree of the app and the dongle if necessary.