for simplicity I would rather take the out from the soundcard, run it thru the Inputs of the virus and connect the virus outputs 2 the amp/ moni. ... this way u can take advantage of the efx and filters in the virus 2 process the PC's master Out ...

Try 2 get an asio driver 4 yer soundcard that supports duplex, then u can work another way... (u might need 2 activate the input on yer sound card but also in cubase, and the press the monitor icon on the input track!!

Z