The TB_SETPARENT message sets the window to which the toolbar control sends notification messages.
TB_SETPARENT wParam = (WPARAM) (HWND) hwndParent; lParam = 0;
The return value is a handle to the previous notification window, or NULL if there is no previous notification window.
The TB_SETPARENT message does not change the parent window that was specified when the control was created. Calling the GetParent function for a toolbar control will return the actual parent window, not the window specified in TB_SETPARENT. To change the control’s parent window, call the SetParent function.