[Pfsense 2.0]DHCP update internal LAN DNS server (BIND)

[franz-unix]

Hi All,
first sorry for my bad english, but I will try to explain the question…
In this day I have installed pfsense 2.0 beta (for testing purpose) due to his new support for custom DHCP configuration.
I wont to setup pfsense's DHCP server in a way that it can update a internal (LAN or DMZ) DNS server (BIND 9 on ubuntu 9.10) using a rndc key.
Reading some tutorials I found that the dhcpd.conf file should appear similar to this (example only)

# Basic stuff to name the server and switch on updating
server-identifier           server;
ddns-updates                on;
ddns-update-style           interim;
ddns-domainname             "localdomain.";
ddns-rev-domainname         "in-addr.arpa.";
ignore                      client-updates;

# This is the key so that DHCP can authenticate it's self to BIND9
key "rndc-key" {
   algorithm   hmac-md5;
   secret	"lgkbhjhtthgtlghtl6567==";
};

log-facility local7;

subnet 192.168.0.0 netmask 255.255.255.0 {
    range                       192.168.0.100 192.168.0.200;
    option broadcast-address    192.168.0.255;
    option routers              192.168.0.1;
    allow                       unknown-clients;

   zone    0.168.192.in-addr.arpa. {
            primary 192.168.0.60;
            key             "rndc-key";
    }

    zone    localdomain. {
            primary 192.168.0.60;
            key             "rndc-key";
    }
}

This are the directive that I wont to insert, but reading in the register of the custom option http://www.iana.org/assignments/bootp-dhcp-parameters/ I don't find them
A solution can be install an external DHCP disabling the built in server, but I prefer to manage all inside the box. Is possible to do this in some way?
Thanks and compliment for the great work