What you only have to do is this: verify if HTTP_HOST
is equals to sitedomain.com
.
If it is then redirect to www.sitedomain.com
.
Try the following (i've omitted https
part)
RewriteCond %{HTTP_HOST} ^sitedomain\.com$
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]