Added 8 minutes later
By the way, I was browsing English-language forums about editing the executable file. The author of NCF, Simoniak, was working on this. He mentioned three years ago that he had managed to add IDs for new art, castles, and abilities, and also to expose some parameters for modification. He also said that he was working on a global mod based on this, but since then, there have been no mentions of this mod; he probably gave up on doing this tedious work. Maybe someone knows his email address; we could write to him and ask for the executable file; perhaps he wouldn't mind sharing it.