Thanks for the script

If you know the AD path to the group already it would probably be easier to open a DirectoryEntry on that, then do a DirectorySearcher from there.

using (DirectoryEntry de = new DirectoryEntry("LDAP://somedomain/CN=FooBar"))
{
   DirectorySearcher search = new DirectorySearcher(de, ("(objectClass=user)"));
}

There is also a flag on the Searcher for whether to drill down to sub containers, I forget the name off hand.