Double Manual support?

Dear friends,

Thought I bought it for the D, I have found myself playing and playing with the Grimaldi the most!  Its such a treat to switch between the Rameau for French music and the Werckmeister for Bach, etc., to increase the action clacking to feel right up close.  I have had numerous real harpsichords in my life, and so I like to tinker with the Pianoteq ones.  Haven't been able to get the Blanchet to my liking, but I find the grimaldi very versatile. 

So here's my question - Do any of you know of a trick I can use to get pianoteq to let me use both my keyboards (which I use for Organ with Hauptwerk) in different registrations?  I feel like I could have more fun with Couperin especially (le tic toc choc, anyone?) if I could have a single 8' on top and a double 8' on the bottom, fussing with the plucking points a bit too for timbral variance.

Many thanks to any with insight on this or any who want to talk about Harpsichords!

Jackie