Proxy ARP and Susefirewall2. HOWTO?

Hi. I have a SuSE 7.3 Prof. machine with 3 NIC's and need to make use of proxy ARP between the DMZ and the External NIC. Is there any support for this kind of networking in the Susefirewall2? My problem is that I'm attached to x.x.x.x/26 net and I'm unable to subnet it more. I have to move only 3 machines, in non-consecutive ip-adresses from the External side to the DMZ. For backup purposes (using Amanda) I have to reach the DMZ machines from the Internal network. One machine is running Windows NT4. Is there an easy and bulletproof solution that also lets me take advantage of the Susefirewall2 script for the firewall logic? /Stefan