Drag'n'drop of sub-tracks/columns

Like for normal tracks, it would be very useful, if dragging of columns within a multi column track was possible. For example I wanna get rid of column 1 later, currently it only seems to be possible to move the righter columns to the left by doing lot of nasty copy-paste operation.

Below the play/off buttons, there is a little space. This one could be the drag handler.

Of course dragging over track boundaries would be result in an overdose of happiness.