Edit: Sorry.. didnt read so closely.. sorry. Dont mind the following message.
hm.. I think that is rather easy...
on *:text:*:?: {
beep 10 100
echo Boing Boing!! You Got A Private Message!!
}
I felt like doing some more, but hey I have forgoten the syntax for time!! lol.
and a tip is not to use this. mIRC got a excellent feature for this in the options->sound check "beep on... Query messages". k?