one word: DON'T.. ehrmm.. that is in fact two words, but you get the picture..
PC's cost little to nutt'n nowadays.. VMWare to control a CNC?.. are you crazy, suicidal, or both?.. CNC controls are not designed for that.. and believe me, unless you are a skilled professional with at least 10 years of experience.. you will not be able to control 2 CNC machines at the same time..