Hi, Daan72.
I was looking to do the same. After extensive Googling, I found that GarageBand doesn't allow manual 3rd party mapping. However, Logic Pro does. (hmmm... can anyone say "upsell"?) I found an extension (Garage Remote) that was touted as being able to override the OS and allow the user to map a keyboard, but alas I had no luck getting it to work. I solved the problem by placing my laptop on the top right side of the keyboard and from there, clicking the software transport buttons.
Rudy
