Creating MFC child dialogs and windows in DLL.

Hi, I need to write some kind of plug-in, which are implemented as separate
dll's. I already wrote a few plugins for this program using MFC and it
worked ok, but now I need to create some GUI inside a plugin.
I have an interface like that

class IModule
{
public:
    virtual void ShowConfDialog( HWND hwndParent ) = 0;
    virtual HWND CreatePanel( HWND hwndParent ) =0; // create child
window, position and size will be
                                                                             
      // controlled by a parent window.
}

But when creating a child windows in MFC I need to pass a parent's CWnd
pointer. Can I create child windows just like that :

HWND CreatePanel( HWND hwndParent )
{
    m_wndParent.Attach( hWndParent );
    m_wndChild.Create( &m_wndParent );
}

or maybe like that:

     m_wndChild.Create( CWnd::FromHandle(hwndParent) );

Which way is correct ? I know about issues with the message passing between
dll and exe, but I solved it already ( plugin can filter all messages from a
message queue ), so I only need to create a child window.

Thanks in advance,
Adam