User & Group from another computer

[Stropher]

I just want to retrieve the users and groups of a given computer with
the following:

string machine = SystemInformati on.ComputerName ;

ManagementObjec tSearcher searcher = new
ManagementObjec tSearcher("SELE CT * FROM Win32_Group where Domain = '" +
machine + "'");
ManagementObjec tSearcher searcher2 = new
ManagementObjec tSearcher("SELE CT Name FROM Win32_UserAccou nt where
Domain = '" + machine + "'");

ManagementObjec tCollection moc = searcher.Get();
ManagementObjec tCollection moc2 = searcher2.Get() ;

ManagementBaseO bject[] names = new ManagementBaseO bject[moc2.Count];
ManagementBaseO bject[] groups = new ManagementBaseO bject[moc.Count];

moc2.CopyTo(nam es, 0);
moc.CopyTo(grou ps, 0);

If I try the above statements in a local computer, it works fine.
But if I change the SystemInformati on.ComputerName with the name of
another computer in network, moc2.Count delivers 0.

Is there anyway I can change the code so as to be able to get users and
groups of a given computer in network?

Thanks in advance
stropher