Cyrillic fonts, Hebrew, or Right to Left (*RtL*) characters are a part of the Non-Unicode character set. There are not recognized within VideoStudio. VideoStudio will only allow Unicode style characters to be used. Only those languages verified with the installation (*Dutch, English, French, German, Italian, Japanese, Traditional Chinese, Simplified Chinese *) can be used.
Should you wish to use a non-verified character within the program, you can use your favourite image editor, to create a transparent image, which contains the text the way you wish it to appear. Once created, you can import that new image into VideoStudio, onto the overlay or text tracks.