There is a feature introduced in 12.2x code Configuration Change Notification and Logging where it allows to record all commands entered in configuration mode that can also be sent to syslog server as well, this feature works great, any command entered in config mode will be recorded saved in router archive defined buffer as well as sent to syslog server.

http://www.cisco.com/en/US/docs/ios/fundamentals/configuration/guide/cf_config-logger.html

Basic configuration is simple

e.i

archive

log config

logging enable

logging size 50

notify syslog

hidekeys

Check Cisco feature navigator in the event your IOS does not have that feature and inquiry for your platform type, or see more details in above link given Table 1 Feature Information for Configuration Change Notification and Logging for detailed IOS codes supported.

http://tools.cisco.com/ITDIT/CFN/

Rgds

-Jorge