Maybe it could be easier to transfer files between the device and the PC through some other sistem as:
- Copy the file to a web site with ftp and the retrieve it from the pc (and viceversa)
- Send the file with a socket connection
- send the file as atachment in a email
You could use the SMB library to copy from the device to the pc. from the pc to the device is more of a problem without connecting the device to USB. An email attachment would work either way, or a server app running on the pc.