Button assign - Help

[ProjectedMusic]

Hi!
Im totally new with QLC and need help setting up the functions properly. I use a DAW (Cubase) and have a track there dedicated to QLC so when I play a MIDI note, that triggers a scene or chaser. I have managed to set up buttons that do what I do, almost.
What I would like to do is have a button that is on for as long as I press it, and then fades out when I release it. I cant seem to figure this out.
Help is very much appreciated, thanks!
Carl from ProjectD

[GGGss]

a flash-function does not have fade possibilities, so you will have to be creative.
I could think of a solution with loopback channels and chases etc - but it's a lot of work simply to have a fade out...