Using Hald CLUT to modify CRI of light source?

Unfortunately the latter is not the case. 100 only means that, depending on the standard you are testing against, 8 or 14 colours are evenly distributed in your light source. This is IMHO not a good measure since it opens doors for cheating by carefully engineering the light sources for the test procedure and not for real life application. Cough … anybody said diesel? … cough. Therefore, more modern tests work with a larger number of colours. It is still possible but less likely that a light source passes the test very well despite being a very bad light source. If you need something to trust more, check the whole spectral distribution.

I still do not really understand your question. Could you please explain a bit deeper what you want to achieve?