I've never tried using libapreq on NT. You should probably look at the mod_perl mailing list. You can find some discussion about libapreq on NT here. There are pre-built binaries available as well.
Comment on Re: Re: Re: Apache::Request, myth or reality?
I just had the same problem on Unix... (yeah, I know I'm replying to something 2 years later...)
But, the key is:
place the cgi in a mod_perl specified dir as per your web configuration!
Bill