Paul, a quick search shows that you can get an aftermare accesory cable for that phone, they plug in to the small USB port on the side of the phone, Nokia simply say they can't guarantee operation but there are lots of anecdotal reports that it works. A search on ebay for 1680 classic data cable will turn up one for under $10 delivered. You should be able to download the nokia suite free and use it. Some more info
here