Inferring from the check-box macro Rahul included I thought he could learn from a SCN document for better check-box management. This method leveraged the before_refresh functionality. Only then did I suggest changes to that method which would accomplish his desired task which leveraged the archaic API. One that was designed for EVDRE's has been regression tested and I can confirm works for EPM reports in all known clients through 24.
Hopefully it'll guide Rahul to his desired functionality.