How to change cell reference for calc based on different cell manually entered value?

I have a spreadsheet with a number of columns

Columns A Column B etc…
Date Numbers

At the top of the spreadsheet I have a manually entered number…in the range 1-10 (ManVar)
In column A I have the date that that row of data applies to
In column B I have a range of increasing number based on externally supplied data
In column F I have a range of numbers based on externally supplied data

Columns D and H have calculations based upon a simple calculation to give me a percentage for the increase from the previous day

However, the data sets are currently uncertain whether the data in Column B and F ‘actually’ happened on that day or up to 10 days earlier,

i.e The simple model would be cell in (Column Fx)/(Column Bx)=PercentageAnswer

but…as there’s potentially a ‘delay’ in the correct date actually matching the model should be

cell in (Column Fx)/(Column B(x-ManVar))=PercentageAnswer

This allows me to ‘toggle’ the ManVar variable at the top of the sheet to see what the change in the dates has on the output percentages.

I hope this explanation is fairly clear, so, how can I get the sheet to use ManVar to change which cells it uses for the calculation

Thanks

Please edit your question to attach a sample file, with notes about what you want achieve, to make for someone help you,

H2: =F2/INDEX(B$2:B$7;ROW()-ManVar)

See sample file.

More LibreOffice Help on ROW, INDEX.

Tested with LibreOffice 6.4.7.2 (x86); OS: Windows 6.1.


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