Location of export_descr_ancillaries.txt

I want to make some ancillaries movable. I don't want to unpack 7 gigs worth of data. I used the unpacker to unpack just export_descr_ancillaries.txt into c:\temp. I edited it the file, now copied it to C:\Program Files\SEGA\Medieval II Total War\data, added the following lines to C:\Program Files\SEGA\Medieval II Total War\medieval2.preference.config, and made that file read only.

[io]
file_first = true

I now load a saved game and see that my ancillaries are still not transferable. Do I need to start a new campaign? Did I place export_descr_ancillaries.txt into the right directory? Miss anything else?

Thank you