Maybe this will do the trick..
ON *:TEXT:*:#: {
$text = $strip($1-,burc)
if (hi isin $text) { msg $nick hi }
}
At least this will ignore any text on the beginning and the end of hi..
But it will also run on words like "high"
I've been out of the scripting business for a while now, but maybe this will word..
You could've found it to if you used the search option

Grtzzz