Dear @wp,
Thanks a lot for your code. It really solved my problem. I would not expected it could be done entirely with FPSpreadseet without requiring SQL queries! In fact, it makes the string grid even redundant, since using a second worksheet for displaying the matrix already does what I need (and it can easily be exported to a csv file anyway).
But... I would still like to be able to have a way to filter rows ("records") in the spreadsheet, using several criteria in SQL-like queries (eg., for displaying only the plants belonging to a certain family, or all specimens from a given family collected at a certain locality, etc.) Is there a way of doing this using the FPSpreadsheet component only? But perhaps it should be better to open a separate topic for this question, since it may be of interest for other users.
With best wishes,