The parallel port is emulated, so there is no real hardware accessed. You're out of luck there. I have no idea if someone made a patch for that - if you are able to compile your own version of dosbox, you might search for it.

Alternatively, you can use the emulator "bochs". It is harder to use, and slower, but it should be able to use your parallel port directly.

it's not a design goal of dosbox. even though somebody might create a patch for it's unlikely that we will commit to the cvs.

Moe,
If I could define what is coming in and out of the Parallel Port, could I set the emulator up to fool the software ?

I do not understand what you are referring to with the word "bochs", can you clarify ?

Bochs is the name of another PC emulator, aimed at complete system emulation. It doesn't come with it's own DOS (so you must have a bootable disk image) and is generally slower, but supports more general-purpose software. Since dosbox is aimed at games, see what qbix says.