I really don't like the WHILE loop in there.

I use this code, (which may or may not be from Jeff Moden) which requires a table of numbers from 1 to 8000:

ALTER FUNCTION dbo.TableFromList(@List varchar(8000))

RETURNS TABLE

AS RETURN

SELECT LTRIM(RTRIM(SUBSTRING(ListID, number+1, CHARINDEX(',', ListID, number+1)-number - 1))) AS Value

FROM (SELECT ',' + @List + ',' AS ListID) AS InnerQuery

JOIN Numbers n

ON n.Number < LEN(InnerQuery.ListID)

WHERE SUBSTRING(ListID, number, 1) = ','