$findtok
From Scriptwiki
Returns the position of the Nth matching token in text.
$findtok(text,token,N,C)
Note that if you specify zero for N, it returns the total number of matching tokens and that it returns $null if it wasn't able to find a token.
Example
echo -ag $findtok(This is a test,a,1,32)
This example would return 3, as a is the third word in the text.
echo -ag $findtok(a.b.b.c.b,b,0,46)
This example would return 3, as there are 3 b's in the text, seperated by dots.