Hi embryo,
Well I don't have experience with the old 6.4 and CGI but if it's running on IIS on Server 2003 I'm sure I can probably assist you with it.
Is this your own Server or is it possible to Remote Desktop access with Admin rights on it, at least initially and then you can remove those rights after the work is done.
I'll reply to your PM and we can go from there. Though Groupee might be able to get you up and running as well since they should be conversant in Windows platforms as well. If not let me know.