ASA version 8.2.2

How do you assign remote access VPN sessions a unique default route?  Other than the default route assigned to the ASA.  For example, my VPN ASA (handles vpn sessions), defaults to the Internet.  I would like remote access VPN sessions to default the internal network first, then follow the default route to the Internet out a different firewall.

The ASA outside interface IP address is a public.  The inside is a 10.x.x.x private.  VPN clients are assigned 172.17.x.x.

Thanks