Is this a calculation or a filter?
The syntax you have included would be valid for a filter, but not for a calculation.
You could break it up like this - the calculation would be:
total([TRL_PRICE]*[TRL_QTY] for [PAR_COMMODITY])
and the filter would be:
[PAR_COMMODITY] = 'FLD'
Or alternatively, if you didn't want to filter as above but just wanted to see the total for the FLD rows, you could create a calculation [COMMODITYTOTAL] using:
if ([PAR_COMMODITY] = 'FLD') then ([TRL_PRICE]*[TRL_QTY]) else (0)
and then use this in another calculation:
total([COMMODITYTOTAL] for [PAR_COMMODITY])
Regards,
MF.