I am in dire straights over here. We just changed our LAN from a 192.168.1.0 to a 172.16.4.0. We run Active Directory in our environment and our gateway is a Cisco 5505 ASA. Since the change, our clients can VPN in and make a connection but cannot RDP to any machines that they need to get to on the LAN that they VPN into. I updated the VPN address pool and DNS servers but I'm not sure what else I need to configure. I can send anything you need as I am not an expert and I really, really appreciate the help!
i'm not familiar with asa too, but you could take a look at ACL's part, from your description it looks like you didn't updated them.