If you download the latest libusb-win32 release, you can use the GUI filter wizard to install the filter driver to that specific device. You do not need an inf file.
Take note that libusb-win32 filter may not work with some device and according to some driver experts that it has no future. BTW, I am one of the admins of libusb-win32 project.
The other way is to change the firmware and have one extra interface without any endpoints. Use WinUSB (or libusb-win32 device driver) for that interface for the vendor specific control transfer.