The Pix uses the "vpngroup" command in much the same way the Concentrator uses groups. You can set up multiple pools and assign them to different group names to build your access-lists from. You would need to use the Cisco Unified Client, which is actually the same as the concentrator client.
Do you need each user to have different access or can each user be place in a group. On the client it uses the group name and password to "authenticate" to the PIX.
You could for example create an ip pool in the 192.168.10.x subnet. In the vpngroup command you specify the name of this pool. In your access-list you allow 192.168.10.x to get to what you want. Then create another pool for another group.
This link might give you some further insight os to how the client is setup.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...