Okay, that became quite a lot simpler. I searched the modding document for "path", and found:
7.48 #magicboost <path> <boost>
Gives a boost or reduction to the monsters magic ability
for one or all magic paths. The boost can be from -5 to 5
levels. See table 11 for path numbers (0-9) . Use number
53 as path to boost all paths at once.