To open this dialog box, click the Language * control that appears in a number of dialog boxes.
For example, you use this dialog box when you create or edit an audio project or work in other dialog boxes.
If you do not find the code you are looking for, it may be the case.
For example, en is the code for English. If you type EN, you will not find English. Or if you are looking for en-BE, you will not find it if you type en-be.
Click the Code Explained link to open
https://www.w3.org/International/questions/qa-choosing-language-tags.
https://www.ethnologue.com/ can help you learn about languages and dialects, and language codes.
Click 
(Change Name) to open the Change Name dialog box. Then you can change the name of the chosen language.
If the font you want to use is not listed, get more help.
The appropriate keyboard is necessary.