Editing the "main cell" changes the data of every cell referring to it, and editing the references, changes the main cell too. Is this possible?

[makiwara]

So I need not a single function, which changes the data (or copies) from one cell to the destination, but from the destination to cell too, if I modify that. (so it works in 2 directions instead of 1)

I edited a picture so it's easy to understand:
https://imgur.com/a/t98U9SS

Is this possible?

 

[Fluff]

Duplicate https://www.mrexcel.com/forum/excel...code-level-100-can-you-solve.html#post5071913

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