hostname - creating a named host for virtualbox accessible from host

For my dev machine, I have windows 7 host with ubuntu guest. I run the guest as the server.

Every time I want to test from the host, I find my current guest IP address, and connect via that (for example, today it is 192.168.1.188:3000/). Of course, this changes every time I connect to a different network.

I want to create a named address, dev.myapp.com that I can connect to from the host windows machine, or possibly any machine on the network (if that is possible, though it may be a security concern, somebody on the network would need to know my url name in order to access, so I'm not that concerned).

I've tried chaning the etc/hosts in ubuntu to include

127.0.0.1:3000 dev.myapp.com

but unfortunately, this isn't resolving from either the host or guest. I'm using a bridged network adapter, promiscuous mode is deny.