>>-COMPARE(string1,string2--+------+--)------------------------><
                            '-,pad-'      

returns 0 if the strings, string1 and string2, are identical. Otherwise, returns the position of the first character that does not match. The shorter string is padded on the right with pad if necessary. The default pad character is a blank.

COMPARE('abc','abc')         ->    0
COMPARE('abc','ak')          ->    2
COMPARE('ab ','ab')          ->    0
COMPARE('ab ','ab',' ')      ->    0
COMPARE('ab ','ab','x')      ->    3
COMPARE('ab-- ','ab','-')    ->    5