Trying to use DragOver event

I have created an Active X control that displays delivery numbers for several locations and times for one week at a time. The information is shown as numbers in labels. I have been able to successfully get details about the information using click and mousemove events.

Now I am trying to allow the user to add deliveries via drag and drop. All I need is to be able to change the backcolor of a label when I drag over it, this will identify where the user will drop or add more deliveries.

My problem is that I am unable to get the dragover event of the labels within the active x control to fire.

I have done searches here and elsewere but I am unable to find any clear answers. Any help is greatly appriciated.