Depends on where you do nat.
If you do nat on router,
ip nat inside source static
(you can additionally specify a port against each ip - either tcp or udp)
If you do nat on the PIX, you will need to configure static commands and access-list to permit a particular port.
You can see some examples here
Thanks for the reply.
I still have nothing.
Here is my router config:
ip address 64.45.175.yyy 255.255.255.xxx secondary
ip address 64.45.175.xxx 255.255.255.yyy
ip nat outside
ip local pool group1 172.16.4.70 172.16.4.100
ip default-gateway 184.108.40.206
ip nat inside source list 102 interface FastEthernet0/1 overload
ip nat inside source static 64.45.175.yyy 172.16.5.37
ip route 0.0.0.0 0.0.0.0 64.45.175.aaa
ip route 172.16.5.0 255.255.255.192 172.16.4.64
haha, thats what I get, been at it to long.
Anyhow, I changed it and still nothing, perhaps it has something to do with my PIX, but I tried to route it, but the PIX can't even ping the address on the router.
Ok, Try bypassing the PIX, and put the server directly on the 172 subnet and see if thats working. This will tell you if the PIX is the culprit.