Roland tr-8 using multiple audio outs via USB in Cubase 7.5

I don’t see a quality problem here (sound is same as from analog out), and every channel actually does transmit their sound. However i would like to know same thing. To utilize TR-8 over USB i need to choose it as a soundcard then i can see TR-8 channels - however if i do that every other I/O setup assigned to my original soundcard is missing (obviously).

So the question is - how do i keep and use my original soundcard and my whole setup, as is - but being able to use Tr-8 as well. I do realize that on Mac they have soundcard cascading sort of so people on Mac can do it natively - but i am on Win and AFAIK when working with ASIO only one card can be utilized.

So the question is how?

I don’t want to use asio4all, i want my original RME driver. Did anyone managed to connect and run in Cubase - original soundcard AND tr-8 via USB at the same time on Windows?

I have more then 20 real input/output assigned to my Cubase via my RME MADI card. And i do need them.