I can tell you 100% that it is possible, as my friends and I did this shortly before trying SoD.
What we ended up with was a computer running as a 'server' and it was hooked into our little LAN, and any time we brought computers over, we could all play. On top of that, you COULD run EQ on that server and play locally there as well though that lagged things a bit.
Minilogin is what you use for logging in. On a side note, minilogin uses your ip address to manage your account login... you could log in with account name adsgadfh and password pooh and if you had the right ip address, it knew who you were. I wrote a webtool and we did some other tweaking that ended up letting you use minilogin over the internet (still not that safe thanks to ip spoofing/masquerading) and we played that way for a bit. So we were able to play local (same machine), on a LAN and over the net.
So, yes, whatever it was you were wanting to do, it's completely possible (UNLESS you want to have a public, distributable, open source login server that is based upon user names and passwords... you'd have to packet-watch it yourself and try to figure out using the EQEmu code and the packets you see to work out the loginserver code).