Port Forwarding

i have an exchange server with ip 192.168.1.1
on my workstation when i type on the web, 192.168.1.1/exchange, a log in menu will pop out… and is running fine.

My router ip is 192.168.1.254 with WAN let say, 202.60.4.3

I have enable the HTTPport forwarding 80 to my server Ip 192.168.1.1, but on the web if i type 202.60.4.3/exchange, web not found.

Any other configuration,?? and teach me how??