it is not WINS as all that does is help in NetBios name resolution. It may be that netbios is not turned on on all the machines, as it would need to be in order for older OS's to browse a network. But win2k and up do not need it in order to see a network. In fact the fact that you can type in a name and get to the machine says that you are not having problems with netbios, WINS, or port blocking (137,138,139 are the netbios family). You are most likey just out of luck with browsing the network.
Let me ask you this. if your workgroups are the same, then if you type in a computer name and it gets to the correct machine does that machine now show up in your workgroup? do all the mahcines now show up? that is what happens on a network here with cisco vpns, NT, 98, 2k and XP boxes. The remotes are XP and can only see the network in network neigborhood once you attempt a connection to machine on a remote network.
also adding all the machines as
192.168.x.1 Dell1001 #DOM:mydomain
192.168.x.2 Dell1002 #DOM:mydomain
192.168.x.3 Dell1003 #DOM:mydomain
would be bad, as it would say that they are all domain controllers, sort of, it is missing a step, but still it would not help. This would if it were a netbios name issue, which it is not.
192.168.x.1 Dell1001 #PRE
192.168.x.2 Dell1002 #PRE
192.168.x.3 Dell1003 #PRE
in any case you may have to just map the remote machines to drive letters on your machine. you can do this with a batch file and have it run with your VPN connection. just use "net use x: \\machine\share" and you are in. unless you need to authenticate, then you need to put that in too, but this is enough for most people. good luck