>Hi everybody,
>
>The description of the problem can be found at http://forums.asp.net/p/1307742/2569516.aspx#2569516
>
>I'm now thinking that it's impossible to do in one step.
>
>Any ideas?
>
>Thanks in advance.

DECLARE @TestOrders TABLE ([Order] int)
DECLARE @NewOrders  TABLE ([OldOrder] int, NewOrder int IDENTITY(1,1))

insert into @TestOrders values (1)
insert into @TestOrders values (2)
insert into @TestOrders values (3)
insert into @TestOrders values (4)
insert into @TestOrders values (5)
insert into @TestOrders values (6)
insert into @TestOrders values (7)
insert into @TestOrders values (8)
insert into @TestOrders values (9)


declare @OriginalOrder int
declare @NewOrder int

set @OriginalOrder = 2
set @NewOrder = 5
INSERT INTO @NewOrders (OldOrder)
SELECT [Order]
FROM @TestOrders
ORDER BY CASE WHEN [Order] = @OriginalOrder
                   then @NewOrder
              WHEN [Order] < @NewOrder
                   THEN [ORDER] 
              ELSE [ORDER] +1 END

UPDATE TestOrders SET [ORDER] = NewOrder.NewOrder
FROM @TestOrders TestOrders
INNER JOIN @NewOrders NewOrder ON TestOrders.[Order] = NewOrder.OldOrder
                                           
select * from @TestOrders ORDER BY [Order]

Please, next time when you give an example use table variables instead of real tables or temp tables :-)
It is very easy to forget to drop them after the example ;-))