Creating subdomain in Amazon AWS Cloud9

Question

I try to create a subdomain site on an Amazon AWS Cloud9 environment. I would like to reach the subdomain server with an URL like:

subdomain.xxxxxxxxxxxxxxxx.vfs.cloud9.eu-west-1.amazonaws.com

It works properly for xxxxxxxxxxxxxxxx.vfs.cloud9.eu-west-1.amazonaws.com

But I can't figure out how to create subdmains. Here is my configuration:

/etc/apache2/sites-enabled/000-default.conf

<VirtualHost *:8080>
        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/html
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined    
</VirtualHost>

/etc/apache2/apache2.conf

<Directory />
        Options FollowSymLinks
        AllowOverride None
        Require all denied
</Directory>

<Directory /usr/share>
        AllowOverride None
        Require all granted
</Directory>

<Directory /var/www/>
        Options Indexes FollowSymLinks
        AllowOverride None
        Require all granted
</Directory>

I tryed to follow the instruction on this page : Creating subdomains in Amazon EC2 but it seems my configuration is not the same.

Anyone could help?