Forward specific port to another ip

[Andy Lego]

Hi,

I would like to forward all requests that come to system a.xx.com at
port 8080 to go to another system b.xx.com to port 80.

For example, I am running a web server on system b.xx.com, but I want
it to look like it is running on a.xx.com on different port.

Also, I want to do this on a.xx.com only, without touching the
firewall or b.xx.com.

Any ideas?

Thank you.

  Andy