Replacing Campaign decks?

[NEMESiS]

Hello, I wanted to know if there is a way to replace the campaign decks with custom built ones? I know kevlahnota managed to do it in this thread:

viewtopic.php?f=101&t=5151

However, it seems that he removed the files. I know that in the Core was there is a "Campaign" folder but when I try to create an overriding file of it the game just creates a broken section for an additional campaign. Also, when editing the Core Wad itself the campaign breaks, so it seems I can't really replace the core wad. Only other thing I can do is override the existing main decks but I don't want to do that. Does anyone have any insight on how to do this? I would greatly appreciate it.