* If you don't use ArtistSort, never mind, let's keep it aside for now.
* MusicBeeSettings.ini/.bak are located in %APPDATA%\MusicBee (in the installed version). You may compare the values of <ArtistSortMapping>...</ArtistSortMapping> in both files: the lost values could still be present in the .bak version, one never knows.
* Anyway, I have prepared several files for you: an extraction formula, a Calc sheet, and some usage notes.
The files are stored in the following cloud folder:
https://drive.google.com/drive/folders/1NBQQb-YqC0VOgtP1ImLKlSqI7AGnfcg8?usp=share_linkSubfolder 'Mp3tag' contains:
* Artist List (csv).mte
* ReadMe.txt (= how to use it)
Subfolder 'LibreOffice' Calc contains:
* ArtistSortMapping.ods
* ReadMe.pdf (= how to use it)
* ArtistSortMapping.Screenshot1.AS IS.jpg (= what ArtistSortMapping.ods should look like when opened with LibreOffice)
* ArtistSortMapping.Screenshot2.EXAMPLES.jpg (= the first screen from my own sort mapping list)
Well, it took me some time to adapt the Calc sheet in particular: I merged the different formulas and defined a layout wich is, I hope, user-friendly enough, or not too user-unfriendly.
As I don't have MS Excel on my computer, I can't test if the formulas are converted correctly.
One more question: do you use MB's function Multiple Artist Splitter for your music files?
In that case, you should extract a list from tag Performer as well.