Return Column as List of Comma Seperated Values

CREATE    PROCEDURE ap_ReturnCSV  
	@SQLstring nvarchar(4000), @ColumnName varchar(25), @list varchar(8000)  OUTPUT 
/*********************************************************************************************************
       NAME: ap_ReturnCSV					Specified by: Bryan Bain
       REQUESTED DATE: 14-OCT-2003				Designed by:  Bryan Bain
								Bryan@HillCountryVillage.com

Requirements:	Returns a comma seperated string of a single column from a select statement

Parameters:	@SQLstring = The complete SELECT statement used to get the column rows
		@ColumnName = The name of the column to use (this would also be in @SQLstring)
		@list = the returned string of comma seperated values
Example: 
--Get CSV list of warehouses 
USE PUBS
declare @SQLstring nvarchar(4000), @ColumnName varchar(25), @list varchar(8000)
SET @SQLstring = 'SELECT * FROM employee'


SET @ColumnName = 'emp_id'

EXEC ap_ReturnCSV @SQLstring, @ColumnName, @list OUTPUT

print @list


REVISION:   REVISIONDATE    	ACTION
--------    ------------        ------
**********************************************************************************************************/


AS  


	BEGIN 
	   DECLARE @newSQL nvarchar(4000)


	   SET @newSQL = 'SELECT DISTINCT CONVERT(varchar(25),' + @ColumnName + ') ' +
			RIGHT(@SQLstring,(LEN(@SQLstring)-CHARINDEX ('FROM' , @SQLstring))+1)


		--convert UIDs to string of comma seperated values
		
		CREATE TABLE #workingtable 
		(
			i int IDENTITY (1, 1) NOT NULL ,
			vc varchar (10),
		) 
		
		insert into #workingtable (vc) EXECUTE sp_executesql @newSQL
		
		
		declare
		    @lasti int
		
		select
		    @list = '',
		    @lasti = 1
		update
		    #workingtable
			set @list = 
				   case
		                       	when @lasti = i then vc
		                       	else @list + ',' + vc
		                   end,
		     	    @lasti = i

	   

	END