I am fairly new to all this myself but..... I think rgt007.dll is a file needed with greenstreet software (a google search for this brought two hits both pointing to greenstreetsoftware.com, one in german and one in french!.
If you have the software disks you could have a look for this on them (goodness knows what you do with it when you find it though, I think it depends on your operating system).
I have Greenstreet software on my system and I have this file in c:\windows\system32 (on XP home).
I hope this is of some help!