help with complex sumproduct, lookup formula

[RichardO]

Hello everyone:

I have calculations to do in column G & H in excel but it's so complex
I don't how to go about it, can you please help.

I have the following columns:

Account name (column A)
Due Date (B)
Date Paid (C)
Outstanding amount (D)
Current Due (E)
Amount Paid (F)

But now I need to calculate a new outstanding amount because th
outstanding amount on the invoice is not always correct. So I have
column: Calculated Oustanding Amount (G). Then, I also need to decid
if there is an issue or not (column H).

For the first month of each account (the first month could b
January/2004 for one account and March/2004 for another), th
Calculated Outstanding Amount (G) is the same as the Outstanding Amoun
(D) because that's all the info available.

For the second and subsequent months of each account, the Calculate
Outstanding Amount (G) is the previous month's
Calculated Outstanding amount(G)+previous month's Current Due(E)
previous month's Amount Paid(F)

I don't know how to write this formula, how do I do this please?

To decide if there is an issue or not (column H), for each account, i
this month's columnG<this month's columnD AND previous month's Dat
paid<previous month's due date, then there is an issue.

I have a sample of the above in a spreadsheet, I don't know if anyon
would like to see it so they can understand it better to help.


Thank you so much for helping me out.

Richard