Pete,
Here are a couple of threads that might get some gears grinding in your head on how to control Cubase ‘remotely’. In this case I’m attempting to help Akai MPK2 users specifically; however, the concepts of building the map(s) in Cubase are fairly universal for most MIDI controllers out there. The main point is…you can bind pretty much any command in Cubase to MIDI events 
http://community.akaipro.com/akai_professional/topics/mpk49-mapping-to-cubase-elements-7
Here is a video on making remote maps. It’s an older version Cubase in the vid, but current versions haven’t changed much if any.
Here is another thread (in which I refer to the link above as well). It branches out into some other ‘remote control related’ topics as well.
Here’s one that tosses up some examples on using the MIDI Logic Editor…