Place these in your custom campaign/map packs's "[]_cfgs" folder (DON'T EXTRACT THE FILE, KEEP IT AS A .ZIP). Then if you want to use them, add them to the bottom of your custom objects.cfg (making sure the ids start at the number directly following the last one on your list). Then in Unearth, add the custom objects with the same name and ID number, and place away!

e.g.

[object150]
Name = ROCK_PILLAR
Genre = DECORATION
AnimationID = ROCK_PILLAR
AnimationSpeed = 0
Size_XY = 0
Size_YZ = 0
MaximumSize = 300
DestroyOnLava = 0
DestroyOnLiquid = 0
Health = 0
FallAcceleration = 0
LightUnaffected = 0
LightIntensity = 0
LightRadius = 0
LightIsDynamic = 0
Properties = CHOWNED_ON_ROOM_CLAIM DESTROYED_ON_ROOM_PLACE