Creates a child frame used for Rich Preview.
CFrameWnd* CreatePreviewFrame(
   CWnd* pParentWnd,
   CDocument* pDoc
);
Parameters
- pParentWnd 
 A pointer to a parent window (usually provided by the Shell).
- pDoc 
 A pointer to a document object, whose content will be previewed.
Return Value
A valid pointer to a CFrameWnd object, or NULL if the creation fails.
Requirements
Header: afxwin.h