Hello Cedric,
Yes - you can setup drag and drop from a grid control (GRID_1.CTL) to the same grid control. If you then enter some PERFORM logic, this logic can do something like;
r1=GRID_1.CTL'draggedrow,c1=GRID_1.CTL'draggedColno
r2=GRID_1.CTL'droppedOnRow,c2=GRID_1.CTL'droppedOnColno
Once you have these drag and drop rows and columns - you can then use them to retrieve the current values (GRID_1.CTL'value$) and other properties of the cells as needed.