Using the cutters that bobtail linked to is what you need.
You cannot model that in V-Carve or for that matter even in Aspire to my knowledge.
I think there is a threading gadget somewhere, but I don't know where.
I have never tried it, but I am pretty sure this would work.
It's a pretty easy combination of x-y motions Either G2 or G3 with a Z added in for the pitch.
It's not something in Vectric - it is straight G-Code.
I will play a little tonight on my machine.
Imagine the Possibilities of a Creative mind