ActiveDocument and Delphi

Does anybody know how to display Office documents like Internet Explorer 4.x
and Visual Studio does.
I think that they're using a technique called ActiveDocument. It seems as if
only Office97 documents is supporting this technique now.
I'm developing a software which should be able to preview different
documents. Now I'm using the OLE-container, but that doesn't look especially
nice. If anyone has a clue how to do this, please help me.
Stefan Johansson