AD_Library.cs

private string _distinguishedName = "OU=test,DC=cwn,DC=org";

DirectoryManagement manager = new DirectoryManager( _distinguishedName );
List<Container> containers = manager.Children;
List<Group> groups = containers.Children;

// Add a new container
Container _container = new Container();
manager.Add( _container );

// Add a new group to a specific container
Group _group = new Group();
Container _testContainer = containers.Children.Find( "test" );
_testContainer.Add( _group );