>So, if i understand rigth, when you set the DisplayFormat, in preview displays this text? But when the report run,display the string rigth? no?

No, no. Preview or Printing the commas are at 3 places like 123,456,789.12 (###,###,##0.00) but my DisplayFormat is specified for the same number to be 12,34,56,789.12 (##,##,##,##0.00)