Hi aliwa,
as far as I know, it's not possible with GWT standalone. If you need special drag and drop operations I could recommend
gwt-dnd.
There you can make your components draggable with different draghandles. (With the makeDraggable(Element, DragHandle)-method)
I remember that Fred Sauer is working with the team of GWT to fit his library into a future version of GWT maybe 2.5.
Hope this helps.
Please contact for further information.
Greetz,
mukarev