Question 3Axis(w/4 step motors) machine

Hi,

I have a 4 axis TB6560 driver board. I need to drive one motor for
X-axis, two motors for Y-axis and 1 for Z-axis. In other words, my CNC
machine has 3 axis (XYZ), but my machine has 1 step motor for x, TWO
motors for the y axis and 1 for z. What is the best way to do that?
Should i make a special input parallel cable jumping each y-axis pins
with the a-axis pins, or you have a better idea?

Thanks,

Carlos Pena
Santo Domingo,
Dominican Republic