Network Neighborhood Subnet

I have inherited responsibilityfor two remote sites, and would like to be able to control the computers from a third location. In W2K (and NT 4.0) Network Neighborhood I can see all the pc’s in my subnet 10.87.xx.xx. I cannot see any pc’s in subnet10.87.yy.yy or 10.87.zz.zz. However, I can ping them by IP and name, can run tracert, and can find them all with Neotrace. Using apps like NetOp and RemotelyAnywhere, I cannot see the pc’s in those subnets. NetOp t/s tells me they use Windows’ browser in their deployment utility to “see” computers, so if Windows doesn’t see them, this app won’t. Any suggestions would be greatly appreciated!