Removing attributes from a reply

I need to remove an A/V from the reply list, but only if another A/V is already there. For example: If I have the Framed-IP-Address attribute, I need to remove any attribute of Cisco-AVPair -~ "ip:addr-pool.*" (because my NAS's will choke on that and that means I have no way for a fall back pool to be defined by radius for my proxy users who may/are assigned IP addresses by my customer) This needs to be done post-proxy stage for my needs. I have been assuming I would need the new CVS head policy feature for this. Anything I am missing? Joe