Is there a way to assign Preset N° to buttons in controllerCCs.csv ?

Hi Patrick,
As far as I know, there is no easy way to choose sample sets with a midi button.
...but...
You can merge them in one sample set, using a different voice for each of them.
Then use CCmap to choose (in the example set you can see 4 voices).

• the controllerCCs.csv is for identifying your keyboard signals to samplerbox
  
• the Controls.csv is the naming of the various features of samplerbox
  
• the CCmap.csv is for binding the two
  

It's all in the docs, but a bit scattered and obscure.
Good luck, Noek