Hi Krishna , you would need adjust your Cube Properties. on the Cube Properties tab, what do you have set for your Consolidation Algorithm Type? I believe you would need to change this to Custom - then attach the Finance Business Rule on the Cube as Business Rule 1 - and handle/address your Custom calc to correctly calc C#OwnerPreAdj.
Take a look in the Admin Guide so you understand the Data Unit Calculation Sequence to understand the order in which Member Formulas run, and Business Rules attached to the Cube execute. Sequence matters when doing custom consolidation rules.
Regards,
Mike G