Cmputil won't help you if you want to look inside the *.grp files. This tool only compresses and inserts a bmp file (for example) into an existing *.grp file. I guess what you are looking for is a file called decompress.exe which actually "unzipps" the *.grp files.
You can get those files here as well :
http://www.commanders-academy.com/fo...=3837#post3837
Cheers
OS