Here's my FileInstall helper. The _SplitPath function was posted by ezzetabi. I just took out the array return bit.
One problem I have is with having to click on the Save button twice for the _SaveList function to be called.
; Listbox constants
Global $LB_GETCURSEL = 0x188
Global $LB_DELETESTRING = 0x182
Global $LB_FINDSTRING = 0x18F
Global $LB_ADDSTRING = 0x180