>Could you go a further in your explaination?
If we were talking about zip codes, ALLTRIM(' 9') # '00009' but
VAL(ALLTRIM(' 9')) == VAL('00009').
My point is to compare the VAL() of the numeric strings rather than the strings themselves. For absolute equality, again for zip codes which are five digits, you can compare:
PADL(VAL(zip_code),5,'0')
This totally eliminates the leading zero issue.
HTH