How to only accept Requests from specific site..?

.htaccess redirect

[djson]

.htaccess file support to redirect a request
for one page to other page.

I wonder if there is a way to control the access
request to the files of some directory by
only allowing requests redirected from
specific link or site.

For example.

If .htaccess file redirect
request for A to B(on the other site),
there is any way to allow access requests
from only A to B.

I want to block any direct access to B and
only allow access from A.

It's unusual case... but I cannot move data
on B to A and it's not possible to create same
.htaccess file automatically because A and B
are located on different machine (site).

[littleman]

If your server is set up to allow you to do so, you could put this in your .htaccess file for site B

SetEnvIfNoCase Referer "domainA\.com" local_ref=1
<FilesMatch "page\.html">
Order Allow,Deny
Allow from env=local_ref
</FilesMatch>

This will only allow triffic with site A to hit "page.html" on site B.