Let’s take a quick example of having a Unit Price and Price Unit in the PurchaseLine table. Here is how you can create a calculated column on the report to show as UnitPrice/PriceUnit.
you can write your customized code to display/return some data on the fly of report and form execution.
Create display method in report datasource level and it will get executed for each table record.
Sample display method:-
display int Grade()
while select grade from salgrade join emp where(emp.SAL>=SALGRADE.LOSAL && emp.SAL<=SALGRADE.HISAL)