You can't as far as I know.
Why would you need to change the tab order so frequently?
i have hundreds of reports daily with different dates. I post/update a record by date so setting the day through tab order makes it a lot easier, i wont have to go back and forth with each field dates.
Yes but why would you need to enter layout mode and change the tab order to do this?
That seems like a very unusual and inefficient layout design. A different design might eliminate the need for this--saving you time as well as making this work for IWP users.