This actually worked, thank you. I’ve located the save files now. Now what, I copy it and (in case the reinstallation of the game deletes those files) just paste it?

Yes, I was planning to download the new version from gog games. But when I installed the game I didn’t think about gog games at all, when searching for games I often go directly to DODI.

Could you explain this Sandboxie method? I don’t understand, what do I have to upload?