The best shot I can give you on this is to create an image of your empty disk. This wil consume a couple of kilobytes on your system since it is empty (mostly zero). Then just use this disk image to create your ramdisk, then it is fully suited for your needs.
On the other hand, you can add the commands to initialize the disk after you create it. As far as I know, 'diskpart' is your commandline tool.
Diskpart won't see a IMDISK created "disk" (basically because IMDISK - notwithstanding the name - doesn't create any disk, but only a volume and it "hooks" at a higher level than what disk manager, diskpart are, i.e. partmgr.sys is not involved).
Olof has written the Arsenal Image Mounter that is actually a miniport driver and that can create actual (virtual) disks (accessible/viewable in disk manager and diskpart).
The member you replied too was given anyway an appropriate answer, the issue was not about creating (and formatting) a new disk, only to do that automatically at each boot, JFYI: