OK, that's a key bit of information, that the files do not have .DLL extensions. That should make it easy, although I'll be shooting in the dark, being unable to test it directly. Fortunately, several brave souls have offered to test for me, so I'll give it a go.
One question for you guys: do the VST3s get identical entries in the registry as VST2s? Except, obviously, for the filename.