You can get USB to ethernet adapterd, but they are going in the wrong direction. The adapters connect to a USB Host, and allow the host to connect to an ethernet network. The phone is ALSO expecting to connect to a USB host. In other words, it won't do what you need.
What you need is something that has a USB host port, as well as an ethernet port, that ALSO has whatever drivers are necessary to control the phone. An example of this might be any OpenWRT-supported router that also supports USB-attached storage, or USB-printers, etc.
Or perhaps a Linux-based NAS, like the DLink DNS323, which also has a USB host port.
Of course, the deciding factor is the availability of drivers for the phone. Can anyone who has signed up for one of these packages tell me how the phone appears to the host PC?