Ok well first off I think you'll find the drives and control won't like running from a VFD, they are not designed for this type of power and the VFD won't like you splitting circuits off it, again they are not designed to be used in this way. Really you need a Rotary phase converter which will let you run it all 3 phase.

However often the Control and drive transformers are often single phase and just run from one leg of the main 3 phase transformer, only the spindle and coolant pumps tend to be 3 phase.
Can you link to a Circuit diagram.?