The VirtFS works as expected for a Fedora Host and Fedora Guest (you must 'sudo modprobe 9p' on the guest). I don't think it's possible as the VirtFS presents a special '9p' posix file system to the guest, and there is no support for that in Windows.
It looks like maybe there
be support someday,
BTW I created a VirtFS for a Win7 here and the VirtFS device 1af4:1009 appears on the PCI bus, biut no driver of course.