MarketPress: translation of "add to cart button"

Hi,

I've read that it is possible to edit "add to cart button" in template-functions.php by changing 'Add to Cart &raquo. However it is not possible to change it to cyrilic this way. My website is oriented to Russian speaking people. When I change encoding into UTF-8 or 16 the website crashes.

How can I translate the button?

Thanks,

tequaz