WillDAQ has hinted at a way that works.
MS Word has vector drawing tools built in, so nothing extra is needed.
So based on MS Word 2003...
Click the arrow drawing tool and draw an arrow, and it is best to do this diagonally.
Set the arrow head shape to design you want.
Copy the arrow and paste a copy of it end to end with the previous one.
Edit the properties of the arrow that points away from the other, and remove its head.
You now have what looks like a line with an arrow head in the middle.
Select one arrow, by clicking it.
Select the other by SHIFT+clicking it.
Both arrows are now selected and highlighted.
Group them.
The grouped object can be copied around as needed.
You'll notice the grouped object has a box around it. At the corners are little white circles and at one edge on a short lead-out a green circle. The object can be stretched and rotated to most angles by dragging one of the white circles at the ends of the line. Fine tuning rotation can be achieved by using the green circle. If you create the construct horizontally or vertically, the resulting object doesn't behave quite right, which is why I recommend creating using diagonals to start with.
I would paste in some diagrams illustrate, but a little busy at the moment.
