I have made an add-in for Word. I would like it too be on top of Word in that session.

When I start I show the form with vbmodal. But when I move the form a "copy" of the form shows in the "wordwindow". I must leave focus from my form when I move the form so that word can repaint the window.
But how can I spot that my form has been moved. I can't find any proper event.
Or maybe it can be solved in some other way without modal.