You can't do a conventional drag in one direction and make the formulas change in the opposite direction.
Here is a solution using OFFSET()
This is the data I used:
A B C
1 1 2 -1
2 83 89 -6
3 6 14 -8
4 80 7 73
5 67 27 40
Column C has the results of A1-B1 etc, just for comparison with the results of my solution.
In a row above the formulas you want to drag, enter a simple series of numbers starting at zero
For this example I put 0 in cell E6, 1 in cell F6, then dragged them to the right to extend the series.
In the next row I put this formula in cell E7:
=OFFSET($A$1,E$6,0)-OFFSET($B$1,E$6,0)Note the $ signs.
Drag this formula right, under the series of numbers 0,1,2,3,etc.
The formula in cell I7 after dragging was:
This is what it looked like:
E F G H I
6 0 1 2 3 4
7 -1 -6 -8 73 40
You will have to adjust this to your exact requirements, but the concept should work!
Please note that OFFSET() is a volatile function, which means that it recalculates every time any cell changes, not just the ones OFFSET refers to. This will add overhead especially with a large number of cells containing OFFSET, and may slow down Excel.