Need help with pulling a value from another workbook based on parameters

[vik2slick]

I'm trying to automate some billing and need to pull Quantities from another workbook based on the Customer Ref. Number (CRN) and Product (Billing Report Field 1) based on the Workbook and Tab Name.

I tried the below Sumproduct formula but I realize this won't work. Appreciate any help offered.

'=SUMPRODUCT(($A5=INDIRECT("'"&O5&P5&Q5&R5&L5&"'!"&"$A$2:$B$20000")*($M5=INDIRECT("'"&O5&P5&Q5&R5&L5&"'!"&"$H$1:$AP$1")*(INDIRECT("'"&O5&P5&Q5&R5&L5&"'!"&"$H$2:$F$20000")))))

Below is a sample screenshot of the fields I'm working with.

 

[GlennUK]

Why are you keeping your base data in separate workbooks? If you have all your data in one place you can do reporting and analysis easily.