If you run Apache on port 80, you can setup an Apache site to proxy to
another web server. For example, I have this Apache site file to forward
all requests for domain2.com to another web server on the local network:
<VirtualHost *.80>
ServerName domain2.com
<Proxy *>
Order deny,allow
Allow from all
</Proxy>
ProxyRequests Off
ProxyPreserveHost On
ProxyPass / http://192.168.1.201:8080/
ProxyPassReverse / http://192.168.1.201:8080/
SetEnv proxy-nokeepalive 1
</VirtualHost>
So all requests that come to domain2.com get proxied to 192.168.1.201:8080.
You may need to install / enable mod_proxy on Apache for this to
work....and Apache HAS to run on port 80. In this case, you would set IIS
to run on 8080 instead.