redirecting links from a specific site elsewhere

[Busarus]

i want to redirect links from a specific domain to my site...
ie
i want to redirect links from a discussion forum to threads on my site to another page with a message for their users

whats the easiest way

 

[louie]

.htaccess

 

[Busarus]

kind of figured that but was hoping for a pointer towards the desired code....

 

[louie]

Redirect 301 /your_page.php http://newdomain.com/newpage.php

 

[Busarus]

nahhh thats not what i want to to

i want to redirect links from a third party site

say there's a thread on here that links to a page on my site

i want to redirect only users who use the link from THIS site to another page

 

[louie]

then you need to get the referer and based on that redirect or not.