[MacEachaidh]

So the coding I had originally doesn't work beyond single digits? That was my question, but no-one's actually answered it yet.

Edited to add:
I've discovered from the Adobe forums that the problem is a bug in ADE, such that it only displays the first digit of the list item number, no matter how many digits there really are.

The specific file I'm working on is for my own use, not for distribution, so in this instance I only need to get it working on my Kobo Touch and/or Aura HD. But of course it would be helpful to have a working solution beyond this one file.