Has anybody done any work on something like a LibreOffice Calc
spreadsheet extension for OpenMAMA, either for retrieving rates or
publishing them?

On the feed handler situation, somebody recently pointed this out to me:

http://csinitiative.com/news/view/collaborative_software_initiative_introduces_open_market_data_feed_handlers/

and the code:

https://github.com/csinitiative/fhce/

Has anybody worked with this? Does anybody feel it is suitable (or not)
for use with OpenMAMA?