/29 IP block over PPPOE

Hi

We have installed a radius server for our user auth via pppoe.

We have this working and operational no problem.

We want to be able to hand out more than 1 public IP to our customers though when they authenticate.

I need to know how to hand out a let say /29 block so that my customer has more than one public IP that they can use.

http://forum.mikrotik.com/t/assign-a-subnet-via-pppoe/56693/1