Thought it wouldn't be that difficult...
I'll include a readme file in the final version.
Available commands:
/xncabout - displays the about window
/xncadd - Adds a name to the list
/xncon - Turn NickChange on
/xncoff - Turn NickChange off
/xncoption - Display the options window, that is also displayed when turning the plugin on
/xncstatus - Displays the actual status of the plugin (On or Off, and if on then Interval etc)
All those commands can also be found in the Plus! menu.. Plus! -> Plugins -> NickChange Plugin
By the way, when you do /xncon, you see the options menu again. When you click Cancel there, off course the plugin isn't turned on!