Excel Summarization of indexed column

[Gateux]

Hi guys!

I have some sheet like this one:

As you can see, by changing number in column A1 is also changing calculation in E5.
Is there any possibility, how to summarize all 3 calculations while E5 still indexed?
I can't just copy+paste characters and then SUM() or make function, my original calculation is in a huge file with many sheets.Unfortunately, I can't use VBA.

Many thanks!
Gateux

 

[Becky]

I think I'm probably missing something here... is there a reason you can't simply do (B5*C5)+(B6*C6)+(B7*C7)?