Install this (the paid version is better though)
http://www.maxmind.com/app/geoip_country
and add this to your .htaccess file:
GeoIPEnable On
GeoIPDBFile /path/to/GeoIP.dat
RewriteEngine on
RewriteCond %{ENV:GEOIP_COUNTRY_CODE} ^RU$
RewriteRule ^(.*)$
http://www.dialerhell.com [L]