freeradius with cisco vpn client

Hi List, I need to replace an old vpn solution with freeradius. The clients connect to a Cisco NAS, which authenticates them with the old radius software, which uses LDAP as backend. The clients use Cisco VPN client. This is the present, and it works. The future should be: Cisco VPN client, Cisco NAS, freeradius and ldap. The freeradius server is installed and configured, it can process requests from command line. The problem is that the Cisco VPN client uses a group name+password pair. The username is given to the NAS with the password "cisco", and the username/password pair should be entered after this. How is this possible with freeradius? I'm using version 1.1. Tbor