Unable to install ramdisk driver, because devmgr does not let you select the inf-file manually for non-PNP-device

Attached bootdisk image contains FreeLDR inside a compressed image file. As FreeLDR stays long enough in realmode, the transition from Syslinux to MEMDISK to 1.44MB RAM DISKETTE to FreeLDR (to ReactOS on harddisk) goes just fine.

A protected mode driver is required to detect this virtual floppy, however I can't find a way to point "Add New Hardware" wizard to the INF file for the needed WinVBlock driver (also present in the attached disk image).

Linux has already proven to be able to find/mount realmode ramdisks from Grub and Syslinux. Windows also, using above mentioned (GPLv3) ramdisk driver. Detecting the virtual floppy in an installed ReactOS would be a first small step to enabling booting from an ISO (or HDD) image located in system memory.
(with advantage of freeing up optical drive, no dependency on mass storage controllers, etc).