HELP! Iptables not working due to VMNET config? trying to open port 80 on VMWindowsGUEST through CentOS5-HOST

Hi,

This has been driving me crazy, its just not working like I think its supposed to.  x.x.x.x is my EXTERNAL Internet IP address on CENTOS5-vmware-HOST. I want to load from public internet http://x.x.x.x:80

GUEST is Windows with VMNET8 (172.16.73.128) "NAT mode" network

I've already edited /etc/vmware/vmnet8/nat/nat.conf  under incomingtcp and i've tried various IPtable rules, yet none has worked.

FYI, x.x.x.x is the IP address for eth0:1 on my CentOS5 vmware HOST server. (ETH0 is another external internet IP, ie a.a.a.a )

I've tried

iptables -t nat -A PREROUTING -i eth0 -p tcp -d x.x.x.x --dport 80 -j DNAT --to-destination 172.16.73.128:80

iptables -t nat -A POSTROUTING -p tcp -s x.x.x.x --dport 80 -j SNAT --to 172.16.73.128:80

and a couple others but its just not working, would appreciate any ideas!