http - Access different apache servers using a single port number -

http - Access different apache servers using a single port number -

i have 3 different web servers in internal lab , each 1 of them have own database , web content. how can access each 1 of them net without mapping different port on firewall each 1 of them?

in other words, can set 4th apache server checks when aconnection comes http://mydomain.com/webserver1 sends user server 1 on internal network , http://mydomain.com/webserver2, redirect him server 2 without having open port other 3 servers main web server? have attached diagram show set up. in advance

apache http