Seems that you are trying to configure a VPN tunnel between a Concentrator and a PIX. Well, to learn how to do that, the best place would be to see the PIX support page. The same can be reached by going to Cisco.com-> Technical Support -> Hardware Support -> Security & VPN Devices -> PIX 500 Series Firewalls. See the Software Configuration section. It has a number of documents dealing with the subject of setting up VPN tunnels between PIX and the VPN Concentrator.