my.domain.se points today to www.domain.se/my

i have put the .htaccess file in my-folder, and i want to break from the my-directory to the root-directory.

my.domain.se/test should point to www.domain.se/index.php?var=test without showing the URL.

---------------------------------
Alias /my /home/web28342/domains/domain.se/public_html
Options +FollowSymLinks 

RewriteEngine On 

RewriteCond %{HTTP_HOST} ^my\.domain\.se [NC] 
RewriteRule ^/?$  /my/index.php [QSA,PT,L] 
RewriteRule !^my(/.*)?$  /my%{REQUEST_URI} [QSA,PT,L]
---------------------------------