RewriteEngine On
RewriteBase /
RedirectMatch 404 /\\.svn(/|$)

RewriteCond %{REQUEST_URI} !^/(register|login)
RewriteRule ^(.*)$ http://www.mydomain.com/$1 [R,L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]