How to delete all files in a folder that don't match some names

Question

Let's say I have a folder with 80 localizations. Since I do speak only two languages, I do not need the remaining 78. Of course I could type del /S /F /Q for every single one of them.

But I wonder if there's a way to specify file names that are to stay, and run a for command for every file in a directory. Is this possible?

Answer 1

The most painless way would be to give a distinguishing attribute to those 2 files:
attrib +R english
attrib +R otherlang
then delete every file that doesn't have that attribute:
del /A:-R *.*
Then you can clear the attributes if you wish.