Use the ON TEXT event:
on @*:text:!warning*:#channel:{
msg # [color:red] !!!!!!!!!!!!!!! WARNING $1- WARNING !!!!!!!!!!!!!
}[/color]
You (or the bot if it's in the bot's mIRC remote) must be opped in the #channel for it to work (change #channel to the channel name).
For further info, see /help on text.
Regards,