Need help setting up XYYZA for stepper motors

My Dual Y 3 axis works fine.  I am trying to setup a 4th rotary axis.  I used the setup wizard for steppers.  I doesn't have a XYYZA  option, only XYZA.
i attached the Y step and direction output to two outputs that appear to drive both Y motors on the Halscope. However without having a Y0 and Y1 as in the 3 axis setup I am hesitant to try driving the steppers as I am not sure they will both act in the same direction.  Looking at the 3 axis setup I would need 5 joints (0.0.0.0.0) to do this.  

Would greatly appreciate some insight.

Thanks in advance