BI: ITEMS and cultures question.

My tiny brain is aching from trying to sort this one and I’m sure it’s something other people may have already been doing for ages in RTW let alone BI…

If I want a culture, say the Huns to use the ITEM files of another culture for it’s 3D in-battle buildings where should I go to edit this? I can do the walls in descr_walls but I can’t find an equivalent for the building ITEMs. Ideally I’d like the huns to use Egyptian buildings but I can’t find a text file that says for example: hun_barracks use hun_barracks.ITEM

I’d be grateful of any help