create function fn_DateToString(@date datetime, @format varchar(20))
returns varchar(20)
as
begin
declare @result varchar(20)
select @result = (replace(replace(replace(@format,'yyyy','20'+substring(convert(char(8),@date,3),7,2)),'MM',substring(convert(char(8),@date,3),4,2)),'dd',substring(convert(char(8),@date,3),1,2)))
return @result
end