Populating a cell based on a formula from another cell....

[Hullybokka]

Hello Excel Forum! My name is Hullybokka I'm from Sydney, Australia.. To be honest I have never been a part of a forum below as we are a bit behind over here!!!! I am really hoping someone out there can help me!!!!! The details of my query can be viewed below... If anyone can help it would be greatly apprecaited!!!

Assumptions:
- A1= order value ($25,000)
- B1= Interest Free Period (months, e.g. 3)

Cash Flow statement for 12-months:
- Row 2 = Months (A2=Month-0, B2=Month-1, C2=Month-2, D2=Month-3, E2=Month-4, F2=Month-5 etc, etc.)
- Row 3 = Order quantities per month (A3=1, B3=0, C3=0, D3=0, E3=1)
- Row 4 = Orders Paid per month.

Question: In Row 4, how do I populate a future month cell which will vary depending on B1 (interest free period) and whether an order was made for that month or not?

Example: An order was made in Month-0 (A3=1) for $25,000 (A1). I want to populate Month-3 (D4) as the month of payment given the interest free period (B1=3).
I want to make it so if I change the interest free period (B1) i.e. 2, 3, 4, 5, etc), from the month ordered the future month of payment is changed...

Confusing I know!!!! Any questions please let me know!!!!

PLEASE!!!!!!!!!

[Hullybokka]

I was thinking of trying to use an IF-formula but it comes up blank....
i.e. In the CELL A4: =IF(A3=0, D4=0, D4=A3*A$1$).

This formula just comes back as false and does nothing... It also doesnt factor in if I wanted to change the interest free period (B1)...

Thoughts?