I have a column in the grid that uses ultradropdown.I allow the user to start typing in what they are searching in the drop down and it auto fills the result. However, what they type is a very long number I am trying to make it a bit more data entry friendly. I want them to  be able to just type the numbers and auto fill the '-'. So it would look like '123-123-123'. However, my drop down will not find anything thing if they search '123123123'. So I was thinking about adding '-' when they started to type. Here is my problem, i can not change the text of the active cell because it is readonly. The cell does not have a value yet because I have not selected one or exited the cell.

Any thoughts on how to make this work?

Thanks