Hi Tobias,
I just checked on a project of mine..
What really matters is the key on the "expression exit" window, that you can see in the up-right corner.
You will notice the note you read there is "2 octave up" the note of the keyswitch. I'd say what is a C0 for VI, is a C2 for Cubase.
For example the C3 for the regular strings you can see in the pic you uploaded triggers a C5.
So you shouldn't have any problem playing those note. Be sure you actualy loaded and selected the VC preset. Hope someone else will help you soon.
To be honest I deleted these keyswitch for choosing the forced string in Dimension from the expression map; to make sense, the expression map should give us the chance to have at least 2 keyswitch triggered simultaniously, one for the chosen string (or the a/b function) and one for the articulation. Otherwise it still happen to have a wrong playback because of a missed keyswitch. So I write the keyswitch for the string in the old way, with long and continuous midi events...
Best,
Fabio