Hi
Have you read the user manual (pg 184 onward) ? You need to read this section carefully to decide which way you want to use the HW VST (particularly read end of page 184 and the start of page 185).
I'm not an expert in this part of using HW but found that I was able to use the system with my external sequencer (after reading pages 184/185 I found what I needed at the start of pg 190).
You may find using the forum Advanced Search feature with "cubase" as the search term provides some helpful results.
Good luck.
Iain