"Virtual light", for modifying intensity

I am trying to use a few IKEA Trådfri LED drivers with non-IKEA LED strips. They work well, but I cant drive the strips at 100% intensity. Lower intensities work well.

So, I need to find a way to make a “virtual” light entity that I can tell “go to 100%”, which in turn will cause the Trådfri to go to, say, 60%.

How can I do this? Can I make a helpe for it?