ok, already solved…
This is a touch screen. Just touch the socket you want to change so it gets highlighted. Then turn the encoder next to the screen to select whatever you want to route to that socket. Press Apply when finished.
Yes, the manual does not state on every page that selecting a parameter of interest needs to be touched on screen… 
@Andreas, Thank you – again. I absolutely hate not being able to solve these things myself. I am old enough and experienced (which means I have made almost every mistake possible at least once) to know enough about this. Seems not…
It was such a simple fix in the end. I was just too fixed on touch screen (blame phones and tablets) to turn the encoder. Dimwit I.
However I still maintain tha an extra paragraph in the manual would have helped.
The guys at Music America were really helpful once they were over my British accent and phoning from the USA.
Yes, you’re not the first who oversee the display encoder, even when totally familiar with it to change values or scroll through scene and library lists. The QuDrive softbutton assignment come into mind (well, that one is documented in the latest manual). Sometimes we elder people just think too complex…
For Pete’s sake! 
I was going to say, please don’t buy a AB168, get an AR2412 since you have a Qu24. Now I read that you did just that GOOD GOOD GOOD!
I have a Qu24 and an AR2412 and love it, using it this Saturday for a show.
Thanks dpdan. The AR2414 turned out to be the better, if slightly more expensive soolution. It also fits nicely into my stage rack and it works perfectly.
One of the most impressive things about the QU-24 + AR2414 setup is that it is utterly viceless. It just works exactly as it should. I am seriously impressed and now that I have spent 2 weeks playing with the QU I am happy to take it to its first show on the 19th. Only about 300 people but I am looking forward to it, not worried about it (or me) at all.
You guys in here have just been great.
Have a fun time with it Pete,
I agree, this is a fun place
And yes, it plugs in and works,
no IP addressses or setup junk > it just works!