Getting different formula outputs for different given inputs

Hi all,

I have a worksheet I'll call TheFormulasheet for now. In this sheet cell A50 eventually gives an output based on a load of formulae and reference tables, and based on the values put in A10, A11, and A12. For multiple reasons it is not possible to edit anything in TheFormulasheet and it should therefore be considered read-only.

Next to this I also have what I call TheDatabasesheet. It's a basic database with slightly over 20k records (rows), using row 1 as a header row containing field names. Now what I basically want for my records is that column M gives the output of A50 from TheFormulasheet when TheFormulasheet's A10, A11, and A12 are using the values in column X, column Y, and column Z in TheDatabasesheet.

In programming language it would probably sound somewhat like this for the first record in column M:

M2 = TheFormulasheet.A50, for when TheFormulasheet.A10 uses X2, and for when TheFormulasheet.A11 uses Y2, and for when TheFormulasheet.A12 uses Z2.

Then I want to auto copy it down for my 20k records. Due to the complexity of everything happening inside TheFormulasheet it is not possible to simply copy the formula behind A50 and paste it for every record.

I have already tried to Google this but I don't even know what this trick is technically called hence I probably haven't found any useful results yet. How do I pull this off?

Thanks in advance!