Problem with return 302 redirection, with Nginx 1.3.11 + Drupal 7

[Mark Alan]

Hello,

In order to redirect certain Drupal 7 functions to https I have
setup Nginx 1.3.11 as follows:

location ~* ^/(\?q=)?(?:user|admin|contact$) {
   return 302 https://$host$request_uri;
}
# and then the usual:
location / { 
   try_files $uri $uri/ /index.php?$args;
}
location = /index.php {
   ...
   fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
   fastcgi_pass ...
}
	
While this works if called as:
http://example.com/user -> becomes https://example.com/user

This fails if called as:
http://example.com/?q=user -> stays http://example.com/?q=user

What should I do to get http://example.com/?q=user redirected to
https://example.com/user or, if that is not possible, to
https://example.com/?q=user ?

Thank you,
M.