This faq has some autoscrolling code in it that is used for scrolling when
you are selecting cells. Maybe something similar will work for you during
D&D.
George Shepherd's Windows Forms FAQ contains an entry entitled:
How can I use a mouse to select cell ranges in my datagrid?
text object >from datagrid A to Datagrid B (right hand side, since i still
have column in right >hand side) , how to i do a drag over and the column in
right handside keep visible >to me ? if anyone can show example for me, that
better .