SuSEfirewall2 SNAT

Hi : I have a little trouble, i am trying to build a firewall with Snat command, simply because, i must to change my ip to 10.1.X.X when i have one, in the net 172.16.1.X example: 172.16.1.X ----> 10.1.X.X 172.16.2.X -----> 10.2.X.X 172.16.3.X ------> 10.3.X.X I´ve tryied using SuSEfirewall2, but only works with masq. I´ve use the file of custom, and write the next rule, just before masq. iptables -t nat -A POSTROUTING -s 172.16.1.0/24 -p tcp -o eth1 -j SNAT --to-source 10.1.1.1-10.1.1.10:1024-32000 but isn´t works, somebody knows how to use SNAT in SuSEfirewall2 ?, because if I try building the rule more general, It filter the packets yet. Sorry, but my english is not good. Thanks.