No M4 macro for ShopSabreIS612 running on WinCNC

I am trying to figure out if there is a way to enable counter-clockwise rotation on my ShopSabre IS612. I have read through the SPIN.MAC and CNC.MAC files and it does not seem like rotation direction is built in into the subroutine. I have also gone the route of trying to change the rotation via the VFD (Mitsubishi A800). The VFD is largely unresponsive to most manual inputs. It is only when I apply a signal to the spindle that the VFD lights up the direction indicator. The Spindle idles at ~1600 RPM, and as such, I am leery of trying to change this setting during operation. Any help you guys could provide would be greatly appreciated.