FreeFlyBertl
Do you still have the X3 installer somewhere? The VS-700 was a "special option" in the installer. You could try to run the X3 installer, but only check the VS-700 option but nothing else ...
I did that yesterday and it didn't work.
So, my solution so far is to do a full install of Sonar X3, then use only Sonar Platinum. That does allow the control surface to be recognized and to work. Also, it's the 2013 version of the VS700.dll, which is what you want.
That German link advises you to install X3, then copy the VS700.dll file from C:\Program Files\Cakewalk\Shared Surfaces and save it somewhere, then uninstall SonarX3, then put VS700.dll back into C:\Program Files\Cakewalk\Shared Surfaces, and run from a command line:
regsvr32 “C:\Program Files\Cakewalk\Shared Surfaces\VS700.dll”
to make sure that the system recognizes it. At that point, you'd have nothing from X3 clogging your system.
Right now I don't want to uninstall X3 though, because with Platinum it also appears that you lose a few other goodies from X3 that I liked. I'm sure one of them will eventually cause a problem, though, so I am ready to nuke X3 as needed.