This is an area under heavy development right now, and I would discourage you from trying to make any headway ahead of the forthcoming 1.0.10 release. Dorico is going to use a modified version of the Cubase VST Expression Maps technology to define the way playing techniques are routed to different channels or switches within channels on your virtual instruments. You will be able to import existing Cubase VST Expression Maps into Dorico and then modify them using a built-in editor. It’s not yet clear exactly how far we’ll get in the 1.0.10 update on all this, but you only have to wait a few weeks to find out.
[edit - Daniel beat me to it, but here’s some context:]
Although some of the naming conventions may look similar, Dorico doesn’t use SoundWorld. In designing Dorico’s playback system we looked at the pain that many users had with soundsets in Sibelius and tried to come up with a system that was easier to control. Many users already have Cubase Expression Maps set up (which also describe mappings between markings such as ‘pizz’ and keyswitches), so we’ve taken those as a starting point. Dorico’s expression maps extend Cubase’s and tie in to concepts that are specific to Dorico.
Since you plan to base Dorico expression maps on Cubase, are the Cubase expression maps documented anywhere that can help us learn more about them and prepare?