Are you an AutoHotkey programmer at all? If so, feel free to modify the source code. You would only have to change one line to make it work with TIF files. Simply change line 57 from:
Loop, %Source_edt%\*.pdf, 0, 0
Loop, %Source_edt%\*.tif, 0, 0
Though, this would still assume the same 12 character format as the PDF files. If you're uneasy doing this yourself, let me know.