VPEA....I've used GPSGate to get USB GPS devices to work. I've used that with the Garmin GPS18 as well. It creates a virtual serial port for you to use. They have a trial period that you can try out as well as a free version with limited features that may suit your needs so you don't have to pay for the full license.
It particularly works well with Garmin products I've found, but I've used it with non-Garmin products, and regular serial port GPS connections as well. There may be other products that do similar things, but I've used that for a while now and found it to work great (for my needs). The documents on their site should help you set it up.
I then use the virtual ports GPS creates in my Labview program and other mapping software as needed.