How to dynamic subdomain for hostname on Zend Framework 1.12?

Question

I want create custom subdomain for mym project with hostname, then i want load application logo based sub domain. I have added below code in bootstrap.php in _initRouter() function.

  $hostnameRoute = new Zend_Controller_Router_Route_Hostname(
':subdomain.domain.com',
array(
    'controller' => 'user',
    'action'     => 'login'
)
);

   $plainPathRoute = new Zend_Controller_Router_Route_Static('');

   $router->addRoute('user', $hostnameRoute->chain($plainPathRoute));

I have below code in htaccess file also.

   RewriteEngine On
   RewriteBase /
   RewriteCond %{REQUEST_FILENAME} -s [OR]
   RewriteCond %{REQUEST_FILENAME} -l [OR]
   RewriteCond %{REQUEST_FILENAME} -d
   RewriteRule ^.*$ - [NC,L]
   RewriteRule ^.*$ index.php [NC,L]

But its is not working after login.