I've already tried it, the problem is that the building icon doesn't show up.
I've found a modder that is doing a lot of changes in the game, but he doesn't have time to show me how to do it... I was wondering if someone there has uncovered the way to do it, I'm trying to locate the icons but, no dice... https://www.moddb.com/mods/dune-iii-the-battle-for-universe