By using
http://www.utf8-chartable.de/ you can replace the english characters with the characters you want like Hebrew or add them to your string.
Also take a look at this include
https://forums.alliedmods.net/showthread.php?t=164789 and you should understand how to use it, but if you are using Hebrew you need to use a Reverse String stock so you could read the word.
You should check out this
http://amxx.pl/topic/52571-include-polskie-znaki/ the real include authors topic, there is a comment which show you a use of this include / hex with the counter-strike 1.6 chat.