LISTING 3: Creation Script for the 
dbo.fn_getelement() UDF

CREATE FUNCTION dbo.fn_getelement
( @ord AS INT,
  @str AS VARCHAR(8000) )
RETURNS INT
AS
BEGIN
  -- If input is invalid, return null.
  IF  @str IS NULL
      OR LEN(@str) = 0
      OR @ord IS NULL
      OR @ord < 1
      -- @ord > [is the] expression that 
calculates the number of elements.
      OR @ord > LEN(@str) - LEN(REPLACE(@str, ',', '')) + 1
    RETURN NULL
  DECLARE @pos AS INT, @curord AS INT
  SELECT @pos = 1, @curord = 1
  -- Find next element's start position and increment index.
  WHILE @curord < @ord
    SELECT
      @pos    = CHARINDEX(',', @str, @pos) + 1,
      @curord = @curord + 1
  RETURN
    CAST(SUBSTRING(@str, @pos,
           CHARINDEX(',', @str + ',', @pos) - @pos) AS INT)
END