Dear Martijn,
You can program as many hot keys as you like in the Cue Editor. Just insert cues and set the 'source' to 'Keyboard', then specify the 'trigger', for example, 'A'.
The cues have the capability of controlling allmost any feature within VisualDMX, alowing you to create all kinds of hot keys.
Please refer to the manual on more examples on how to program cues.
Good luck