Thank you guys, I was stuck during last tentatives with the old 1.3 stable version I've been using for a while in order to get everything show up properly in P3D.
I'll get the dev build of MCX and give it a try asap, hopefully I get a chance next week end.
My next question is, how do we exclude a specific generic building from an existing scenery to place our converted objects ?
In my case, I want to replace a generic building in Lausanne airport with the real one, but as far as I can see all the AD buildings and objects are compiled in the same file : removing this file would remove everything...
Thanks in advance