Extending UTF-8 character rendering

[JahirahDK]

Apologies if this is an obvious question but I have no experience in addon development...
I'm a big fan of the ingame TinyPad editor but often miss the ability to make use of basic symbols and other alt-codes and I've long been wondering if it would be possible to extend the number of UTF-8 characters renderable ingame.

Is it be possible to extend the UTF-8 support range for an ingame editor? Maybe by adding a file containing the necessary character encoding information or?....