If the font is the one that's available from <a href="http://www.urbanfonts.com/fonts/Perestroika.htm">http://www.urbanfonts.com/fonts/Perestroika.htm</a>, then it was designed for a "faux Cyrillic" effect (it doesn't even contain half the Cyrillic alphabet), so it is not good for legitimate Cyrillic use.<br>
<br>If you use Times New Roman, you will not need to define commands \russ and \rusp, you can type Latin and Cyrillic seamlessly -- just use \setmainfont{Times New Roman}.<br><br>Andrew<br>