;-) Of course it's possible in theory. As for actually doing it....
One thought that occurrs to me would be to use a decompiler to expand the software into a form that an editor would understand. Then look thought it to sort out the subroutines, then to compile each subroutine separately and to run each of them until you find the one you want.
Bear in mind that it's obviously more complicated than that; the subroutine you want may require certain resources to have been made available ahead of time by the main program, for example.
Mind you, my own programming days were on the Vic20 and later Commodore64, so take my musings with a grain of salt....
