creating vba script to write semi complex formula across 1000+cells in 1 column

I'm entering the home stretch in my project, and the last piece is to tie the various figures together.

On my master sheet, I have my starting stock for products A and B for each customer and "today's count" which is calculated from here:

=SUM(F2+DAILY!$AF2+DAILY!$AF3+DAILY!$AF5+SUM(HISTORICAL!$F2:HISTORICAL!$BO3,HISTORICAL!$F5:$BO5))

This formula takes the starting stock, current regular and custom orders and new stock, historical regular and custom orders and new stock, adds
them all together and reports what we would currently have. Product B is calculated in a similar manner:

=SUM(F3+DAILY!$AF3+DAILY!$AF4+DAILY!$AF6+SUM(HISTORICAL!$F3:HISTORICAL!$BO3,HISTORICAL!$F6:$BO6))

The second customer's formula would be this for product A:

=SUM(F4+DAILY!$AF8+DAILY!$AF9+DAILY!$AF11+SUM(HISTORICAL!$F8:HISTORICAL!$BO9,HISTORICAL!$F11:$BO11))

Product B would be

=SUM(F5+DAILY!$AF10+DAILY!$AF12,HISTORICAL!$F10:HISTORICAL!$BO10,HISTORICAL!$F12:HISTORICAL!$BO12)

From what i've been able to learn so far (which is just enough to get in trouble :P) an array should help, but i don't really understand how to use them for something like this....

Thanks.

I don't think I'm trying to create a function or do calculations in VBA, more creating a "script". Let me try to explain my goal a different way.

I want to have excel write formulas to my "today's count" cells (all located in a single column) using predefined lists of values, lets call them X Y and Z.

I want to assign values of 3,7 and 11 to X
I want to assign values of 2,5 and 6 to Y
I want to assign values of 8,9 and 4 to Z.

For the first cell, I want VBA to write a formula with the first values on each list, so let's say i want to write =sum(Fx+Gy-Hz) where VBA looks up the first value in X (3), Y (2) and Z (8) and the end result that is written to the cell is =sum(F3+G2-H8). In the second cell, I want it to write =sum(F7+G5-H9) and so on.