I can't find my USB to USB lead, sorry. I'll take a look through the cupboards.
In the mean time, I'd definitely use your network to copy those files.
If you have a shared area on your PC, you can use ES File Explorer to access them.
Open ES File Explorer, scroll to the right so the Network tab is on screen. Now click the New button, then select LAN. Enter in your PC's IP address, and a user name & password (if you've not set one specifically for the share, it'll probably be your Windows login user name and password). Click OK, and you'll see a new shortcut under the LAN section. Select it, and navigate around your PC's shared folder(s)/drive(s). If you've allowed read-write access you'll be able to copy or move files from your Android device to your PC.
If you prefer, you could do this in reverse, by using Samba Filesharing for Android - see the last section here -
http://droidboxforums.com/threads/local-network-based-apps.101/ . This way you'll be able to access your DroidBOX's files (non-system ones) on your PC, and copy and paste them that way round instead.