Then you should learn. Read about if-then-else, then you can check if a nick is a certain one, and make the script react accordingly.
Or, write the stuff to a inifile in the format
[MESSAGES]
nick=message goes here
nick2=message2 goes here
and then use
on @*:JOIN:#channelname: if ($readini(filename.ini,MESSAGES,$nick)) .notice $nick $ifmatch
