Xen with routing an bridging

[Thore <thore@datensumpf.de>]

Hello, merry christmas at all,
after setting aup my laptop on wheezy now I got back to the 
konfiguration of my server.
I have running there 3 dom0 with bridged IPv4.
I have an subnet for IPv6 with a lot of adresses and i want to use them 
(my home system has tunneled IPv6)
An IPv4 subnet is too expensive at the hoster and IPv6 will be 
availiable for everyone soon.
So I want to set up two more systems with IPv6 and give every system an 
own IPv6 address.  (the domU hasn't konfigured it yet)
My question is, how can I set it up?
 Something like this (from hetzner)

# Loopback-Adapter
auto lo
iface lo inet loopback
#
# LAN-Schnittstelle
auto eth0
iface eth0 inet static
  # Haupt-IP-Adresse des Servers
  address 192.168.0.250
  # Netzmaske 255.255.255.255 (/32) unabhängig von der
  # realen Netzaufteilung (z.B. /27)
  netmask 255.255.255.255
  # Explizite Hostroute zum Gateway
  gateway 192.168.0.1
  pointopoint 192.168.0.1
#
iface eth0 inet6 static
  # Haupt-IPv6-Adresse des Servers
  address 2a01:4f8:61:20e1::2
  netmask 64
  gateway fe80::1

I have only an eth0 and a xenbr0

somehow I must add the /64 subnet and tell xend that I use routing too.
I don't know can I use the xenbr0 or have I to create a xenbr1 and configure an eth1 in the dom0s

And how can I than use systems only with IPv6.
I had to ask my questions earlyer, now I had forgotten a lot.
Hope you can understand and help me
Sorry for my english

Thore

P.S: The Adresses are all only examples from the hetzner wiki