Assembly: Microsoft.Office.Interop.Word (in microsoft.office.interop.word.dll)
The Document object is a member of the Documents collection. The Documents collection contains all the Document objects that are currently open in Microsoft Word.
UseDocuments(index) where index is the document name or index number to return a single Document object.
The index number represents the position of the document in the Documents collection.
Use the ActiveDocument property to refer to the document with the focus.