How to create a keyboard for a dead language?

Question

A language which is not predefined on any operating system, for example; Demotic language which is the third version of the Egyptian language.

Answer 1

Ok, this is new. I will need more info. Do you want a physical keyboard? Do you want the Demotic language using Windows?

Answer 2

You need ascii code for that language.

Answer 3

RKK thanks, I will google it.

Answer 4

Fernando Pozzetti
Thanks for ur answer Frenando!
Yes, I want to use it on Windows.