Can the whole countries be playable? Or not

[bitw]

I want to play as a different country which don't appear, I think someone knows how to do that, I searched how to unlock the whole countries to be playable, and that's it:"You need to make the countries playable in the game files. Go to the supreme ruler file location, Sandbox then open the Cg2020 and CG2020_Settings and make all countries playable, 1=unplayable 0=playable."
How can I do that? If someone knows, help me, please!

[Zuikaku]

Some regions, for some unknown reasons, are not playable by default. But there is a workaround. Start a new sandbox, select some random region to play. Save the game and exit. Move the save file to multiplayer folder. Load the game in multiplayer selecting region you really want to play. save the game. Move the save game file from multiplayer save folder to single player save folder. Load in single player. And that's it