Modifying descr_ancillaries data

Hi. I'm playing the "Retrofit Mod" which integrates some units from Kingdoms campaigns into the Grand Campaign of MTW 2. It includes of course several unpacked files from the data folder such as export_descr_units or descr_buildings and the like which you can easily edit to your own likings but it does not include the descr_ancillaries files which I would also very much like to modify. After inserting the unpacked descr_ancillaries.txt from the main game into the mod's data folder myself and changing some entries there it still doesn't work. Does anyone of you know how to make the mod use the modified data instead of refering still to the original game's files? e.g. I changed the Ark of the Covenant's dread bonus to +5 but in the game it still gave only +2 dread. Thanx.

Use io.file_first or run it via a modfolder + bat file.

To make changes to the EDU take effect in the Britania campaign, do I just rewrite the io.file_first.bat file to refer to british_isle folder and put it in there?