IR Report Computation Expression Column Name

Question

I am trying to generate a custom Report based on the Existing IR Report Conditions.
One of My IR Report have a Computation column with Expression as To_Char(trunc(Y, 'YEAR'), 'YYYY') Where Y is the Column Identifier.
My requirement is to substitute the Column Identifiers with the Exact column Name.
For Ex: TO_CHAR(trunc(Report_Date, 'YEAR'), 'YYYY') where Report_Date is the Actual Column to be used. Apex substitutes the Identifier as Y.
Another Example is CASE WHEN A = 10 THEN B + C ELSE B END
Where A,B and C should be Substituted by their respective column Names.
Is there a way to trace the column name used in the Expression or Frame the Expression with the Column Name.
Hope i am clear in my Requirement.
Thanks
Sridhar

Answer 1

Parse the statement character by character, and if the character is not surrounded by others except for a set of tokens (eg "'(),; ) then you have found an identifier. You can then map it to the correct column name by querying apex_application_ir_rpt and retrieving the report columns, mapping them to an identifier, and retrieving computation specifics from apex_application_ir_comp.
But really, don't do this. (DON'T) It's a load of code and prone to errors. There is no simple way to parse these. It's a fun exercise, that's all.
Rather tell us about what you're really trying to achieve. Why do you need a custom report when you already have the IR with the filters and computations on it?