Z3TA 2 is a great synth, and in terms of sound could be considered a similar synth to the Virus, but to my eyes the layout is nothing like a Virus C which is more knobs than sliders. The image above appears to be Z3TA+ 1. You can see Z3TA+ 2 here:
http://asp-gfx6.com/uploads/posts/d67/d67c2_.jpg
Actually when I think about a soft synth that strips it down to the basic knobs you'd see on the front of a Virus C, Dune comes to mind as a good (very easy to tweak) Virus software substitute that sounds great, although the physical placement of things differs from the Virus (as all of them will).
http://www.synapse-audio.com/dune.html