Happy Holidays

I have a question because I don't know if this is possible in MySQL alone, if it is I might restructure some tables.

1: If I have a row with this:
Code MySQL:
VARCHAR "1,2,3,4,5"

2: I do a simple sub-query:
Code MySQL:
FROM	otherTable
WHERE	id = 12
AND			id NOT IN	(
	SELECT lists FROM firstTable
	WHERE id = 12

Q: Instead of comparing items NOT IN the string of "1,2,3,4,5" ---
Is there a way to make those values separate so you can compare it with 1 then 2 then 3, etc?

I realize this might cause 10x more work on MySQL's part, but I'll only be using this for one set of items at a time.