Yes, you can do so. Open Devices > Device Setup > Generic Remote.
Upper part is list incoming MIDI data, bottom part is list of functions, which will be triggered by these MIDI messages. Please, search the Operation Manual and Forum about Generic Remote Device.
You would need something that puts out midi notes. An expression pedal doesn’t trigger the Generic Remote.
Very powerful control Generic Remote. Like Martin was saying, you can map a midi event that you choose to any command in Cubase (pretty much).
The problem comes in setting this up in a template so you don’t have to do it every time you start a new song.
It’s not really a problem, you just have to set the GR up at the top of your project where you don’t change anything.
So like if you map a bunch of functions out then add a new one to the top of the list, all the functions below it get shifted to the next command and not the ones you wanted them to be mapped to.
This is my recollection, haven’t used it in a long time, maybe it’s different now.