next thing you might wish to do is de-compile the "setup.inx" script file

find a progie called "sid.zip"

quote from readme:

[sid] - installshield 6/7 script decompiler
v1.0 written by sn00pee

introduction
------------
sid is designed to decompile installshield .inx scripts created with
installshield 6 or 7. additionally it allows the user to take a few
changes to the code and patch the script.

END quote

I found this file at protools.com