Integrate .htaccess with usergroup permissions

[titodj]

I want to restrict access to a directory and all its contents to a certain usergroup.
And I think it could be done if you make a (redirect forum or a link within that forum) only visible to that usergroup.
And (here is the tricky part) make htaccess allow just from that exact link...
Something like this...

 <Directory />
   Order deny, allow
   Deny from all
   Allow from .domain.com/vb/showthread.php?t=14327
 </Directory>

The idea being that only a link from a specific predetermined place within the above sample directive allow access to that directory.

I know that you can prevent hot linking this way from outside but Im not sure how it can be coded to get the above results...

Example of hot linking protection....

SetEnvIfNoCase Referer "^http://www.your-domain-name-here.com/" locally_linked=1
SetEnvIfNoCase Referer "^http://www.your-domain-name-here.com$" locally_linked=1
SetEnvIfNoCase Referer "^http://your-domain-name-here.com/" locally_linked=1
SetEnvIfNoCase Referer "^http://your-domain-name-here.com$" locally_linked=1
SetEnvIfNoCase Referer "^$" locally_linked=1
<FilesMatch "\.(gif|png|jpe?g)$">
  Order Allow,Deny
  Allow from env=locally_linked
</FilesMatch>

May be someone can help modify this to work...