C:\Users[YourName]\Documents\IISExpress\config\applicationhost.config
Add this row to the bindings element
<binding bindinginformation="*:yyyy:xxx.xxx.xxx.xxx" protocol="http" />
where yyyy is your chosen port number and xxx.xxx.xxx.xxx is IP address on your network.
Run these two commands in a admin cmd prompt
netsh http add urlacl url=http://xxx.xxx.xxx.xxx:yyyyy/ user=everyone
netsh advfirewall firewall add rule name="IISExpressWeb" dir=in protocol=tcp localport=1914 profile=private remoteip=localsubnet action=allow