Aren't they already there? Check ARSSE/script/OnPlayerSpeak.txt there should be this somewhere:
if $MESSAGE = !admin
/say An admin was requested
IRCmsg $PLAYER_NAME requested an admin on $SERVER_IP:$SERVER_PORT!
ADMINMSG $PLAYER_NAME requested an admin on $SERVER_NAME!!
endif
If lines are prefixed with # remove it(sign, not line).