>>PS: Is there an 'EVAL' function/UDF available for firebird?
> Please clarify, what would the EVAL function do?

Evaluating an expression, a 'formula parser', so to speak.

Some replies to my original question got me thinking on performance
implications, and *maybe* the big nested if/switch statements is slowing
it down... If that's true, maybe offloading the work with formulas and
parsers (instead of hardcoding the logic in SP) might work... But i need
something working on the server side, hence the 'eval udf' question.

Regards,
sugi.