Calculate Break even month

Hello all - Needed some help and guidance on how I can get the break even month for the below scenario. Any assistance would be much appreciated.

C2,D2,E2,F2...: I have headers for 24 months (Month 1, Month 2, Month 3...) ​
Every row (below the above quoted header) is a customer record, with revenue (every month) that I am making over 24 months
Row 3 is Customer Record 1 and C3,D3,E3,F3..: Has a $ revenue figure that I earn each month (for the 24 months) from Customer 1
Row 4 is Customer Record 2 and C4,D4,E4,F4..: Has a $ revenue figure that I earn each month (for the 24 months) from Customer 2
B3,B4,B5...: Has a $ cost that I have invested to acquire a customer account (Example: $300,$250...)

My need is to calculate in which month do I recover the cost of acquisition quoted on B3,B4,B5...
Example: Customer 1 - I recover all the costs in Month 4, Customer 2 - I recover all the costs in Month 6 ​

Thanks
V

Fast answers need clear examples. Post a small Excel sheet (not a picture) showing realistic & representative sample data WITHOUT confidential information (10-20 rows, not thousands...) and some manually calculated results. Just before posting, scroll down to GO ADVANCED, click, and then scroll down to MANAGE ATTACHMENTS and click again. Now follow the instructions at the top of that screen.

Hi Belinda - Thanks for the feedback. Much appreciate it. I have included an attachment.

Thanks
[V]

=MATCH($B2,SUBTOTAL(9,OFFSET($C2,,,,COLUMN($C2:$R2)-COLUMN($C2))))

Enter with Ctrl+Shift+Enter (array formula)

Thanks heaps. It worked. Much appreciate it.

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