Renumbering

[irene]

I'm numbering all my classical disks separately, and inside this group I want a separate numbering for one group. The sorting in both groups is by composer, which I don't plan to change. How can I renumber (not manually) starting from a certain number? I gave this group a different category, so if there is no other choice, I'll number them manually.

I also want to number all the non-classics separately, but not start from One again. These are quite a lot of disks.