Apache Port Config

[L. V. Lammert]

Is there a way to have a virtual host listen on a port to which the main 
server does not, .. e.g.

<Main Server>
        Port 81
        Port 443
</Main Server>
<VirtualHost IP>
        Port 80
</VirtualHost>

Even with the port directive in the VirtualHost stanza, it still listens on 
Port 81 and not Port 80.

        TIA,