LoadModule proxy_module lib/httpd/mod_proxy.so
LoadModule proxy_http_module lib/httpd/mod_proxy_http.so

<Proxy *>
   Order allow,deny
   Allow from all
 </Proxy>

<VirtualHost *:80>

    ServerName app1.somehost.com
    ProxyPass / http://localhost:3000/
    ProxyPassReverse / http://localhost:3000/

</VirtualHost>

<VirtualHost *:80>

    ServerName app2.somehost.com
    ProxyPass / http://localhost:3001/
    ProxyPassReverse / http://localhost:3001/

</VirtualHost>