How to allow sites on local subnet that are not registered in DNS

On the "Manage House Rules" settings page, I need to add a Windows local machine name (NetBIOS name) for the home server to the "Specific web sites to allow" exceptions list. The computers on the home network, which run Norton 360 and Norton Family, access the home server's website at http://homeserver (that is the complete URL, there is no ".com" or other domain qualifier). I have added the IP address for the home server, but can't add the URL. Note that the home server's name is resolved by an entry in the C:\Windows\System32\drivers\etc\HOSTS file.