It is possible, I have not tested this as I use VPN IP pool instead, but based on this documentyou can assign up to 10 dhcp servers for the VPN clients to be assigned IP addresses by windows AD DHCP or any other DHCP server.
In remote access connection profile
Tunnel-group VPN_Group_TEST type remote-access
tunnel-group VPN_Group_TEST general-attributes
dhcp-server
tunnel-group VPN_Group_TEST ipsec-attributes
pre-shared-key **********
See dhcp-server
http://www.cisco.com/en/US/docs/security/asa/asa80/command/reference/d2.html#wp1859817
HTH
Rgds
Jorge
Jorge Rodriguez