The easiest way is to define Bookmarks
in Word for the locations that you wish to paste the charts to. In Word 2003, if I recall correctly, the option is on the Insert menu, Bookmark. Position the cursor firstly, Insert, Bookmark (Ctrl-Shift-F5) give it a name such as bkChart1 (without spaces). Then:
word.ActiveDocument.Bookmarks("bkChart1").Range.PasteAndFormat
' there are other Paste methods, or PasteSpecial
If you prefer to format the document, and the pasted object, using code then you would do well to record a few macros in Word. It won't create perfect code, but it will help you to discover the methods and properties that you need.