How to insert a Word (or cvs) document or Video file to a Word document with AppleScript?
The closest I have gotten is by adding, not the file, but a link to the file, like so: 

tell application "Microsoft Word"
    tell active document
        set ContTemp to content of text object
        set StartRange to (count of ContTemp) - 1
        set endrange to StartRange
        set theRange to create range start StartRange end endrange
        make new hyperlink object at end with properties {text to display:CommentText, hyperlink address:FilePath, text object:theRange}
    end tell
end tell