Tente acessar o aplicativo na porta 9999 usando o link
<VirtualHost *:80>
ServerAdmin [email protected]
ServerName www.example.com
ServerAlias example.com
ProxyRequests Off
<Proxy *>
Order deny,allow
Allow from all
</Proxy>
ProxyPass / http://localhost:9999/
ProxyPassReverse / http://localhost:9999/
ProxyPassReverseCookiePath / /
</VirtualHost>