ChangingImperator Italicus?

[V.T. Marvin]

The file you are probably looking for should be export_descr_units.txt (or EDU for short). Read the descriptions for particular entries at the top of the file, than try to search for "Imperator Italicus" or "Italian general" or whatever the name is and tweak the numbers accordingly.
Or even replace it with the values for "Equites Consulares" - including the references to texture and model files. It should give you them as the recruitable generals in Italy. I do not have the acces to the EDU right now, but once you orient yourself a bit in the file, it should become pretty straightforward.

God luck!