CNC Lathe Threading

I have a new 13x40 3HP engine lathe that I want to convert to CNC.
One of the main reasons for conversion was to be able to do single
point threading, Internal and external.

It has suddenly occured to me that I will not be able to thread at all
after I change the lead screw to a ball screw.

Would someone please explain what I will have to do to to regain this
feature of the machines operation?

Thank you.

Wally6800.