In game mission tabs, 'Historical', etc,

[mongoose]

At the moment, only 3 tabs for mission types in game, which is sort of hard to change due to the bmp files which are no doubt associated with the dlgmistypes.xml if not other dialog xmls. While I suppose that I could make a new bmp and replace one of the 3, I don't see that I can add a 4th tab.
So I tried just adding missions into a sub folder under 'historical' but that did not show up.
Any ideas if either idea can be done?

[gecko]

It is possible to change the labels, but I don't think you will be able to add additional ones.

[Daiwilletti]

Take a look at what Clive did with BoB as a starter. Do a comparison with the stock to see what he needed to change.

[mongoose]

I am assuming 3 tabs is more or less set, and I don't actually want to change the names, although I might have to. What I was wondering is why sub folders and contents won't show at all, and is there some dialog xml or something that could change that. If not, then I might have to rename.