SQL Server - Construir un Stored procedure con la siguiente función

CREATE function dbo.XXXXX (@s varchar(1000), @from_list varchar(100), @to_list varchar(100), @separator char(1) = ';') returns varchar(1000) as

begin

declare @from_len int, @from_CurPos int, @from_PrevPos int

declare @to_len int, @to_CurPos int, @to_PrevPos int

declare @done bit

set @from_len = LEN(@from_list) + 1

set @to_len = LEN(@to_list) + 1

set @from_CurPos = 1

set @to_CurPos = 1

set @from_PrevPos = @from_CurPos

set @to_PrevPos = @to_CurPos

WHILE @from_CurPos < @from_len + 1

BEGIN

set @done = 0

IF SUBSTRING(@from_list + @separator, @from_CurPos, 1) = @separator

BEGIN

WHILE (not @done = 1) and (@to_CurPos < @to_len + 1)

BEGIN

IF SUBSTRING(@to_list + @separator, @to_CurPos, 1) = @separator

BEGIN

set @s = replace(@s, SUBSTRING(@from_list, @from_PrevPos, @from_CurPos - @from_PrevPos), SUBSTRING(@to_list, @to_PrevPos, @to_CurPos - @to_PrevPos))

SET @to_PrevPos = @to_CurPos + 1

set @done = 1

END

SET @to_CurPos = @to_CurPos + 1

END

SET @from_PrevPos = @from_CurPos + 1

END

SET @from_CurPos = @from_CurPos + 1

END

return @s

end

CREATE PROCEDURE dbo.TuProcedure (

@s varchar(1000) output

, @from_list varchar(100)

, @to_list varchar(100)

, @separator char(1) = ';')

AS

begin

----- El cuerpo de tu funcion

-----

----- En lugar de hacer un RETURN @s

SELECT @s

end