I just had to do something related a week ago.
If you look at http://doc.tiki.org/Unified-Index you’ll see that the title_initial and title_firstword so you can use them.
In my case I needed to filter them so: http://doc.tiki.org/PluginList-filter-control-block#Tracker_items_title_that_start_with_the_letter_B
Now it may be a bit tedious but at least you can use 26 plugin List to filter by letter and organise them. ?