Also maybe try this:
 Code:
   ; Specify an actual graphic and hyperlink
   $sPicFile = "d:\gbvlogo.gif"
   $sLinkFile = "http://kixtart.org"

   ; Create new document.
   $objWord = CreateObject("Word.Application")
   $oDoc = $objWord.Documents.Add

   ; Insert a picture.
   $oILPic = $oDoc.InlineShapes.AddPicture($oDoc.Content, $sPicFile, 1)

   ; Add a hyperlink for the picture.
   $oDoc.Hyperlinks.Add($oILPic.Range, $sLinkFile)

   ; Use the InlineShapes Property to reference the object.
   $oHLink = $oDoc.InlineShapes(1).Hyperlink

Translated this from: http://support.microsoft.com/kb/212572