Mach3?.
You need a pci parallel port card to achieve this and add the second port. But,,, they don't always work.
The best guarateed option is to get a new external controller.
Forget Chinese stuff, forget usb. Both are hit and miss.
Go straight for ethernet.
The 4 best options imo are:
ESS Smoothstepper.
UC400eth.
AXBB-E.
UC300eth.
The UC400eth being the cheapest of the 3 that need lpt breakout boards adding on. You can still use the one you have via a db25-idc26 cable.
The axbb-e is an all in one.