I think he means this (below) ArchiCAD's standard Infobox bar at the top with properties for any selected element.
ArchiCAD's Infobox already has an "intensity" control for any light object as you can see, but I don't believe it's related or connected to the one you have for the Corona light when you click on the actual light and open the properties dialog box, since your "Intensity" control is in real world values (Lumens, Candelas, watts, etc) while the ArchiCAD one on the infobox is just a gradation of percentage (out of 100%).
If I understand him correctly, he would like to be able to control the Corona light directly from ArchiCAD's infobox (without using the standard (%) intensity control, but instead using the Corona Intensity value control but not having to open the properties dialog.
Does that make sense?
Yes, that is exactly what I was trying to describe. Thank you!
Infobox shows selected settinsgs of the tool (wall, object, light, etc). It help user to access some settings easily without opening any window. You can modify it under Options/Work Env/Info Box.. menu. I dont know is it something you can do without GRAPHISOFT, but I hope you can :)