I'm not sure I understand your idea about shapes. :)
Here's another idea

* Moved Event of moveable columns
This.Parent.Column1.ColumnOrder = 1
This.Parent.ColumnN.ColumnOrder = N

>Oops, what I meant to say ...
>
>.LockColumnsLeft = 1 works for the left edge. I'm hoping there's a more general solution.
>
>What do you think about my idea of floating a transparent shape over my left and rightmost headers to "cloak" these controls from mouse events that would result in their movement or sizing? Seems like a miserable hack ... on the otherhand, I can't see any downsides?
>