Enable rollover in the Mach4 config for the axis you want as rotational.
If you want to command to 270 from zero but you want the move to go clockwise not counter clockwise you command it 170 then 270.
Here's an example of moving counter clockwise 30 degrees and then clockwise 30 degrees from 0 without rotating all the way back over:
rc = mc.mcCntlGcodeExecuteWait(inst, "G00 A0 B0")
if rc ~= mc.MERROR_NOERROR then mc.mcCntlCycleStop(inst) return end
rc = mc.mcCntlGcodeExecuteWait(inst, "G00 A330 B330")
if rc ~= mc.MERROR_NOERROR then mc.mcCntlCycleStop(inst) return end
rc = mc.mcCntlGcodeExecuteWait(inst, "G00 A360 B360")
if rc ~= mc.MERROR_NOERROR then mc.mcCntlCycleStop(inst) return end
rc = mc.mcCntlGcodeExecuteWait(inst, "G00 A0 B0")
if rc ~= mc.MERROR_NOERROR then mc.mcCntlCycleStop(inst) return end
rc = mc.mcCntlGcodeExecuteWait(inst, "G00 A30 B30")
if rc ~= mc.MERROR_NOERROR then mc.mcCntlCycleStop(inst) return end