draging files from exlorer?

[Saintium]

I would like to be able to drag files from the file manager but i cant figure out how to identify them.
I'm using a file list box but i would prefer explorer.
What should the "Sender, Source" be to "Accept" from the explorer or IE?

procedure TForm1.ListView1DragOver(Sender, Source: ??????; X, Y: Integer; State: TDragState; var Accept: Boolean);
begin
Accept := Source is ?????;
end;