Apache - allowing requests only from certain referrers?

How can I set up a page so that it can be requested from specific
other pages?
Assume I have page1.html.
I don't want people to be able to type http://mydomain1.com/page1.html
into the browser and be able to access my page. If they do that, I
want to redirect them to http://mydomain2.com/page1.html.... Then on
mydomain2.com/page1.html there will be a link to
http://mydomain1.com/page1.html, and that should be the only way to
access mydomain1.com/page1.html...?

I'm running Apache on Windows 2000.

Thanks!