Creating polyobject dummy sectors in WadAuthor

How do I create sector with 'void'-space block in the middle that can be then used as a polyobject? I making a Hexen map and I can't figure out how to do this in WadAuthor.
"Make Column" does not create non-playable-space kind of sectors I need.

Simply enable the "make column" option in the sector creation dialog.

But that does not result same kind of sectors like in ex_polyo.wad -- in ex_polyo.wad when you move your mouse cursor over the door sections inside the dummy sector (using sector selection mode), it doesn't get highlighted, but "Make Column" type sectors do and thus do not seem to be same thing.

Oh, I got it. You must reload the WAD before it takes effect.