ASP - SUBSTRING con NOT IN en consulta SQL

Create FUNCTION Split(@String nvarchar(4000), @Delimiter char(1))

RETURNS @Results TABLE (Items nvarchar(4000))

AS

    BEGIN

    DECLARE @INDEX INT

    DECLARE @SLICE nvarchar(4000)

    SELECT @INDEX = 1

    IF @String IS NULL RETURN

 WHILE @INDEX !=0

        BEGIN

         SELECT @INDEX = CHARINDEX(@Delimiter,@STRING)

         IF @INDEX !=0

          SELECT @SLICE = LEFT(@STRING,@INDEX - 1)

         ELSE

          SELECT @SLICE = @STRING

         INSERT INTO @Results(Items) VALUES(@SLICE)

         SELECT @STRING = RIGHT(@STRING,LEN(@STRING) - @INDEX)

         IF LEN(@STRING) = 0 BREAK

    END

    RETURN

END