it could work :)
As a start step:
http://www.weberdev.com/get_example-3261.html(http://www.weberdev.com/get_example-3261.html)
http://www.techrepublic.com/article/take-advantage-of-php-and-ldap-authentication-for-windows-and-unix/5032010(http://www.techrepublic.com/article/take-advantage-of-php-and-ldap-authentication-for-windows-and-unix/5032010)
http://adldap.sourceforge.net(http://adldap.sourceforge.net)