What is wrong in this Expression?

Hi guys,

i am facing an error on function below. This function works fine, but when need validate the report cames with erros and my cliente said this is problem to acceppt.

Follow the expression.

substring(substring(timestamp2string(_add_years (date2timestamp(AsOfDate ());-1));3;4);1;2)

  • 'A’
    Returns 12 A ( current year + letter A)

There is another awaya to return this on Cognos…based Oracle database.