Text Formatting ⇒ Index Formatting

[forest]

Hi everyone,

I would like to ask if anyone can help me with the following:

When I create and index it sorts the entries by the name and then adds the page numbers where these entries appeared. I would like to change the page number to the problem number (i am working on a book containing a large set of problems and would like to index the authors by their name and the numbers of the problems they proposed).

For example right now it looks something like this

Author 1, 4-5, 7, 10, and so on (these are page numbers)

and I would like it to look something like

Author Junior 1, 2-3, 6, 11 (these are the problem numbers).

Thank you in advance!