Options +FollowSymLinks
RewriteEngine on

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([a-zA-Z0-9.-/]+)$ index.php?msite=$1 [L,QSA,NC]
RewriteRule ^([a-zA-Z0-9.-/]+)/$ index.php?msite=$1 [L,QSA,NC]