Restricting URLs using Active Directory in Weblogic 10.3 - where to start?

Question

Hi,

We are looking to use an Active Directory server to restrict access to certain URLs in our Spring application on a Weblogic server and I have no idea where to start. The problem should be quite simple as I understand it, we have a simple app which has a number of URLs:

<root>/page1.do
<root>/page2.do
<root>/page3.do 
etc.

And an Active Directory servers which lists the users in two groups, such as "Admin" and "User". We would like it so that based on the login information provided (no SSO required), anyone in "Admin" can access all pages, anyone in "User" can only access page2.do and page3.do.

I have absolutely no idea where to start and Google isn't being very forthcoming. I would have hoped that this is an easy task (add AD server to weblogic, set up a config file). Anyone have any experience with this and links to good places to get started or a summary of what we will need to do to get it working in this fashion?

Cheers