I learn python from time to time when I want to write simple script for myself so my answer could be wrong.

I found it in python (standalone not poser's python folder):
c:Python24Liblib-tkTkinter.py
open that file and go to the very end of it. You'll see an example with :

    # The following three commands are needed so the window pops
    # up on top on Windows...
    root.iconify()
    root.update()
    root.deiconify()

I personaly use it and it gives me the focus on main window after the script was executed.