You could add 180˚ to the H component in the HSB numbers.
But quite frankly I wonder about the value of the approach you described.
As I stated above, I know it is somewhat rudimentary but I have not figured out any better way at this point. I also need to add that I forgot to mention that I would like to use this method more for B and W neutral prints. At any rate, I am trying to quantify and identify the exact color cast one may get on a B and W print and then trying to neutralize that same cast with an adjustment layer of some sort. You seem to have another way around this, would you care to elaborate.
If you are talking about b/w prints a Hue/Saturation Layer (with Saturation 0) or a Black & White Layer might be viable approaches.
Of course that is assuming that your output device is reliable, calibrated and capable so to speak.