Conversion to a religion trigger

Well i know little about modding so i want to get a straight answer from somebody knowledgeable. Anyway, in M2TW Kingdoms in the Teutonic campaign, at some point Lithuania has the option to convert to catholicism. Now i was wondering, could this trigger/option be used in a mod ? For example a pagan faction converting to Christianity or whatever. I am not a huge expert so sorry if this something oblivious or stupid to ask.

Yeah there seems to be a change religion keyword. It requires a bit of coding for the units and such though and so far nobody told me what qualifies a unit to be "pagan".
However it won't work with the medieval2.exe, only with the kingdoms.exe