RewriteEngine On
RewriteCond %{HTTP_HOST} .
RewriteCond %{HTTP_HOST} !^www.domainname.net [NC]
RewriteRule ^(.*) http://www.domainname.net/$1 [R=301,NC,L]

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

#Redirect to www
RewriteEngine On
RewriteCond %{HTTP_HOST} ^[^.]+.[^.]+$
RewriteCond %{HTTPS}s ^on(s)|
RewriteRule ^ http%1://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]