>>-POS(needle,haystack--+--------+--)--------------------------><
                        '-,start-'      

returns the position of one string, needle, in another, haystack. (See also the INDEX and LASTPOS functions.) Returns 0 if needle is the null string or is not found or if start is greater than the length of haystack. By default the search starts at the first character of haystack (that is, the value of start is 1). You can override this by specifying start (which must be a positive whole number), the point at which the search starts.

POS('day','Saturday')       ->    6
POS('x','abc def ghi')      ->    0
POS(' ','abc def ghi')      ->    4
POS(' ','abc def ghi',5)    ->    8