take a look at VisualCut or use
http://www.kenhamady.com/bookmarks.html
to see reviews of different add on products.
I know VisualCut would let you burst the report into PDFs with bookmarks and might have a table of contents trick.
Ido has added some new features I have not yet had a chance to play with or deploy into any of my processes.
Since you want this to preclude the printing process you have to use a process that takes advantage of the calculations that happen in an early data pass. Whileprintingrecords would give you results to late to use but is essentially what you would need to get to the printed page number. You would need to use a sub report that replicates the report to pull that in.
The other issue here is that you are not really doing any "grouping" per se, just different group sections in the same group.
There is an interesting SAP blog on this process using a sub report process to build a sting with page numbers...
You can also do an internet search on 'crystal report table of contents' for some more ideas.
However, I think you might consider your end game of the purpose of the table of contents and would something like VisualCut's bookmarks might end up being more effective.
Edited by DBlank - 26 Nov 2014 at 5:27am