Accessing CDocument-member functions

I´m creating a simple single-document application using the MFC wizard which for demonstration purposes prints various textmessages in the document window. Those can be selected by a few options in the menu-bar. I tried to implement the handler (something like ON_FILE_NEWMSG) for this Menu-option in the main program (in my case, Demo.cpp). However, to access a function (settext(CString)) I defined in the Document class I guess I need to use a pointer to the document to call the function that will change the text line ( something like ptrtodoc->settext("Hello world"); ).
The problem about this is that I don´t know how to get this pointer. I know that there is a function called CSingledocTemplate that somehow creates and links the mainframe, the view and the document, but this just returns a Pointer to a SingledocTemplate. Besides, I´m not sure if this pointer is global, so it probably wouldn´t be of any use anyway.
Please help, as this is REALLY beginning to bug me..

If you used the AppWizard, you will have a funtion called GetDocument() in your view. To get the pointer to the document just use:

CMyDocument* pDoc = GetDocument();

then

pDoc->MyDocumentFunction();

to run a funciton in the document object.

[Alek]

CMyDocument *MyDoc = (CMyDocument *)GetDocument();
Mydoc->settext("Hello world");