My purpose is to develop a UDF to link legacy spreadsheets content to a
central database.

I am trying to develop a UDF function that writes its arguments to a
database.
ex: DBWRITE(DSN,stored_proc_name, arg1, arg2, ...). The function would
return 'OK' or an error msg depending on how the transaction completes.

In order to minimize the traffic to the db, I would like to _delay_ the
calculation of the cells containing this UDF until the user clicks on a
'submit' button. But at the same time, I would like this to only affect
the formulas where the UDF arguments have changed, and all other cells
should continue to calculate normally.

Any idea on how this could be achieved ?