WEBIVAN

RewriteCond %{HTTP_HOST}  ^(www\.)?mydomen1.ru$  [NC]
RewriteRule ^index\.php/xxx(/.*)?$         http://mydomen2.ru/yyy$1 [L,R=301]

RewriteRule ^/admin.*$ /admin.php [NC,L]
RewriteRule ^.*$ /index.php [NC,L]