The use of isin operator has a drawback: it triggers if someone named LittleJohn is called while your own nickname is DaJohnny.

The best method will have to be regex, but if regex is unbeknownst to you, you should at least do:

if ($istok($strip($1-),$me,32)) {

You really should use isin instead of $1, what if your name is John and I say Hey John? your nick would be placed at $2. Or if I say Hey you going to be on tomorrow John? now it becomes $8. Also what's up with the CallerNick? just redundant. if CallerNick is $nick why have the word CallerNick? and you know the purpose of the caller why have it say so much? also this snippet wont let you know if someone said your name when you are away from your computer or on another site so why not aline it? And maybe add some color.

on 1:TEXT:*:#: {
if ($me isin $$1-)
window @Nick
aline @Nick 4,1 $nick 11in4 $chan 11at4 $timestamp $1-
/echo -a $nick called you in $chan
}