You don't have to have a driver but you can request one
here. The Instrument I/I Assistant could be used or you could write something of your own. There are shipping examples of serial communication. Just open the Example Finder and do a search for serial. With the programming manual, see what you can get to work. I would recomend that you first try to communicate with the instrument with a program like Hyperterminal before trying to write any code. That way, you can debug any problmes you might have with com settings or the cable type.