The bookmark in NSE was of some "font" I found in the game. The ROM actually uses a font that is stored as 2bpp, which NSE does not natively support.
So in other-words, unless one were to write a plugin for it, you can't edit the font in NSE...
Usually I would take this opportunity to write such a plugin, but I am WAY TOOO busy at the moment...
-School, scouts, driving classes, other extra-curriculars, and making my video game.
If I do have time this weekend, I might look into it, but since I have absolutely no idea where the font is stored in the game, and if it even is 2bpp, I can't make any promises.
If you know C# though, this could be a fun project for you, NSE 2.X provides a library for writing some pretty intense plugins :)