<IfModule mod_rewrite.c>
RewriteCond %{HTTPS} !=on
RewriteCond %{HTTP_HOST} !^www\..+$ [NC]
RewriteCond %{HTTP_HOST} !^subdomainismi\..+$ [NC]
RewriteCond %{HTTP_HOST} !=localhost [NC]
RewriteCond %{HTTP_HOST} !=127.0.0.1
RewriteRule ^ http://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
</IfModule>