There is not a way to define the Server type right out of the box. If you executed your script based on the output you could set a Server Property to denote physical or virtual with the blcli:
Or if you use BSA to manage your virtual systems there are some properties which BSA sets, perhaps you could work of these. A bit more info about this is here:
Another way would be to create a component based on the hw info properties or something else like that, then the server group based on the existent of that component/template on the server.