Format Property Problem

Hi everyone!
I'm working to a report that prints costs!
In a textbox I've done a sum between 2 other textboxes that I've in the report.
It works, but there's a problem... since it's a "calculated field" only in the report layout, in the dataset there isn't its
"format field" and I can't print it in the format ****,00.
I thought that could be usefull copy in its format property, the format property of another field but it doesn't work.
I'm wondering if there's another way, maybe filling the property format with a letter; in fact to cut the hour from the date
fields I put a "d" in the format property of the field.
every replies will be appreciated.

Thanks!