Dreamweaver table add-in menu item

When I open the menu to insert a table, I can hold down the mouse and drag over the table image of the menu to select how many cols/rows I want to insert. I wonder how can I make a menu that works similarly ? (dragging the mouse without losing the focus on the menu and do no create the effect of separating the whole item out of the menu itself)

Thanks

If I understand what you're describing, and I'm not sure I do adequately, you're describing a custom control (one that may take the position of and function in the context of a menu).

Without knowing more about the exact nature of your design intent I might easily go on a tangent. However, the general topics that relate to your inquiry are SetCapture, ReleaseCapture (these control the focus of the mouse messages), various draw operations which may be on a client DC, and of course some state tracking to indicate when such a drag has begun, which ties into the mouse down/up messages.

With more specifics of your intent I can be of more help in reply.