Mounting external usb harddisk (ext4) in virtual box in windows

I would like to mount my external linux formatted usb harddrive in a virtual machine. The host is windows 7. Unfortunately virtual box doesn't enumerate the external harddrive in the options menu of the virtual machine, even though it shows all other devices connected to the host.

Windows can find the harddrive, but obviously just gives me the option to reformat it, because it doesn't support ext4. (ext2fsd or Ext2Read are no options, as I need newer ext4 features)

How can I add a filter for my external harddrive so it is recognized by my virtual machine?

I found the resolution to my problem: Virtual Box doesn't yet support usb 3.0, so those devices aren't enumerated! All I had to do was to plug the usb harddrive into a USB 2.0 port. I should have known better...