well, there's a few ways to do that I think... but a down-and-dirty way is to filter on manufacturer...
like you can pick whatever report, and as long as you inner join tblassetcustom, you can put this in the WHERE clause:
tblAssetCustom.Manufacturer not like '%VMWare%' and tblAssetCustom.Manufacturer not like '%Microsoft%'
I mean that's probably not the best way, but that weeds out VMWare VM's and Microsoft HyperV's at any rate...
someone can probably post a better solution...