Hi Ulrich,
As David mentioned, this forum is for users of Notation Composer, Notation Musician, and Notation Player.
There are a number of other notation applications out there, and each of them has various settings and such for VST instruments or other ways to connect sounds to the notation score. Please do check to see if there's a forum for your particular software. You'll get much better help that way
ttfn,
Sherry