I have two columns of data which seperately may have duplicates but when
combined are unique numbers.
example:
Row Col. A Col. B Col. Z
1 4 101 =A1&B1
2 4 101 =A2&B2
3 4 101 =A3&B3

I would like to use the countif function to validate the combined. Right
now the countif validation is checking against the formula and value but I
just want to check against the final value.

Any thoughts?