GameFont.tga and FontButtonIndex of stuff

OK, I'm kinda new in this modding stuff and now it comes to this tricky part. I dug some info and find out how to edit the tga and how to add new things into it. So, I added new icons for new resources and bind them in "CIV4ArtDefines_Bonus.xml". It runs fine.

Now, the problem is, I can't find "FontButtonIndex" info for other things (like religions and corporations). I want to add new religions and stuff. But how can I bind their little icons to them? I can't find any xml files with relevant info. What I'm missing here?

Yeah, the FontButtonIndex is sadly missing there.

The icons are just associated in the same way they are in the XML.
Means the first 2 icons will be tied to the first religion, the 3rd and 4th to the second religion, and so on. After all religions got their icons, the remaining are associated with the corps.
That also means that if you want to add an religion, you have to move all the corp icons further to insert the religion icons.
Yes, that's pretty bad (and is purely awful if you don't use the asaf's gamefont editor).

Oh, ok I get it. It's time for some Photoshop work then (That editor doesn't work on my PC, dunno why). Anyway, thanks for the answer.