Redirect HTTP from root to subdirectory

.htaccess

#setting for mysite.com linking to /subdir

RewriteEngine on 
RewriteBase /

# Avoid Loop on directory
RewriteCond %{REQUEST_URI} !^/subdir/

# Rewrites all URLS [Replace "domain" with the actual domain, without the TLD (.com, .net, .biz, etc)]
RewriteCond %{HTTP_HOST} ^(www\.)?mysite.com\.

# Rewrite all those to insert /folder
RewriteRule ^(.*)$ /subdir/$1 [L]