That will certainly do something, but I think it will be something you don't want.

Consider a table with these numbers in it: (1, 2, 4, 5). If your number is 2 (which is present), and you select the count of numbers that do not match that, you get 3 (the non-matching numbers are 1, 4, 5). If your number is 3 (which is not present), and you select the same thing, you get 4 (every number there).

What you want is to tell whether a given number is there or not. What you're suggesting is to count (or list) every number that isn't the given number.