Thanks for the replies.
I managed to get this working with "manage scenes".
It seems to me that the "manage scenes" functionality is not very well developed. You can't modify an existing scene, for example - you are forced to create a new one and then delete the old one.
Also, the dialog box takes an age to open, and when you save a scene it takes a very long time to close (like 10 seconds).
Does anyone else have this problem?
I'm running 2013 on Windows 7, on an i7 processor with 8GB RAM - so it's not exactly a sluggish machine.
Thanks
Stu