Yeah.... I suspected that might be your question.
You can. The Firefly software allows you to define your own "actions" for the keys on the remote (most of them, I don't think you can re-assign the Firefly key) to do any "button press" you want. However, you have to manually hack the Firefly "Profile". This involved manually changing text files (I don't think they were even as pleasant as XML).
However, I just saw with the current version of the Firefly software there is a program at: C:\Program Files\SnapStream Media\Firefly\ProfileEditor.exe that looks like (if you run it) it could be a simpler GUI to do it...
When I was considering the same thing, I looked into it and read all kinds of threads over at the Snapstream Forums.... In the end, I decided my time was worth more than the cost of the cheap version of Girder 4. BTW -- For most MC stuff, you DON'T need the fancier versions of Girder...