With the Vice C64 emulator I've got a tool called 'petcat', which converts BASIC (ascii text) to a .prg file for running in Vice. Previsouly I've been able to develop in TextMate and set up a key-press 'bundle' in there to make a shell call out to pet cat, passing in $FILENAME type variables, and this creates the .prg file okay.
Is it possible to do this in Xcode?