Setting up a basic http proxy?

[DJ AM_Juicebox <dj.am.juicebox@xxxxxxxxx>]

Hi,

I'm looking to run apache as a proxy for web development. I'm running mac ox 10.5.4, which already has apache 2.2.8 installed and running.

I'd like to point my _javascript_ files (which are running locally on my machine) to:
  
  http://localhost/test.php

which would hit the local apache server, then have that apache instance forward to my real remote server:

  http://www.mysite.com/test.php

I've looked at a few walkthroughs but they seem to be out of date. I'm wondering if there's a recent how-to on setting this up - the doc here:

  http://httpd.apache.org/docs/2.0/mod/mod_proxy.html

gives a basic example, but I'm not sure where that text should be added - to http.conf? Do I simply add it there, then restart the server?

Thanks