I am currently running my company's intranet on Linux Mandrake using Apache web server with the pages written in PHP. We currently have users who dial into the network who have access to the intranet, I need to find a way of stopping access to the user to certain pages when they dial in. Is there a way using an IP address range on the system to prevent them gaining access to certain areas of the intranet or any other method

Usually for Intranet in almost companys they use Firewall. This type of firewall not only Control the access of Internet/Intranet but also controls webaccess. The best if you could visit this webpage http://www.squid-cache.org/ Squid capability to stop invaders/users entering specific webpages running on intranet. PHP supported!