Actualy you don't need an internet connection to use ip address. Each computer in LAN has an internal IP address you can discover by runing
ipconfig /all
in cmd.
You can use the ip address of the server (probabily something like 192.168.0.x or 10.0.0.x) to access the website remotely.
If you found the ip and still cannot access the website, it means WAMP is not configured to respond to that name ( what did you call me? 192.168.0.3? That's not my name. I'm Localhost ) and you have to modify ....../apache/config/httpd.conf
Listen *:80