To work around the issue of having a virtual server, you can use solutions such as USB over Network. Also certain virtualization software like VMware allows access to the USB port of the server directly. Chaos Group has tested both solutions and they were successful. Keep in mind that Chaos Group does not officially support either of these methods and warns that may not work in every case.
The following links contain more info:
http://www.usb-over-network.com/
Most virtualization software like VMware allows a locally attached USB device to connect to a virtual machine. In cases where there are no available USB ports, a USB to Ethernet hub is a possible solution. Digi Network, Silex, and Belkin offers USB hubs that will work in this type of situation.