To Brett Kaiser
Why so difficult?
You can create function:
CREATE FUNCTION GetAllOnLine(@id int)
RETURNS VARCHAR(8000)
AS
BEGIN
DECLARE @Result VARCHAR(8000)
SET @Result = ''

SELECT @Result = @Result + col2 + ' ,'
FROM YourTable
WHERE col1=@id

RETURN @Result
END

And use it:

SELECT Col1, GetAllOnLine(Col1)
FROM YourTable