to spread figures with equal interval but different starting column

[shahid079]

For some analysis I wish to spread the recovery of MONTHLY sales
amount according to:

- a particular %age of sales amount (eg., 5%) and
- with equal interval value between the receipt months starting from
the month of sale (eg., 1).

The result of the above scenerio will appear like this:


A B C
D E E
1 Month# Sales M1
M2 M3 M4

2 M1 10,000 500
- 500 -
3 M2 20,000 -
1000 - 1000
4 M3 25,000 -
- 1250 -

Thanks! for giving your time even if the above is undone.