Hello,
the most comprehensive collection of IOS commands can be found on the documentation CD, check if you can access this link:
Cisco Documentation
http://www.cisco.com/univercd/home/home.htm
There are also a number of undocumented commands, a listing can be found here:
Undocumented Cisco IOS Router Commands
http://www.tech-forums.net/computer/topic/28883.html
HTH,
GP