For fun and with @capink's guidance I built an action chain that searches the current column for initial text. For example, if you click in the title column and run this chain then it will:
- ask you what character(s) you wish to search for
- find the correct rows (books)
- create a temporary virtual library for the results.
When you run the chain it presents you with this dialog:
Enter the text, 1 or more letters, into the "search_for" box. If you want the search to use the current virtual library, change use_vl to anything except "no". If you don't want the temporary virtual library, i.e. you want only the search, change the set_vl box to anything except 'yes'. The chain does the work when you press OK.
If you've clicked in the title column the chain searches title_sort. If in the series column the chain searches series_sort. If in the authors column the chain searches author_sort.