Looking for a validation rule to validate data after transformation and before loading to the cube.

I have Import/validate/Load workflow.

After the validation step , I want to run a business rule that can do the following -

1. Sum up the amount for all records with the same Product code in the transformed table.

2. Check if SUM = 0 for individual product code.

3. If step2 is validated for all product code , then proceed for LOAD step, else error out.

PS- I know this can be achieved via a confirmation rule but i want to validate before loading to the cube.

One idea that i thought is to execute a validation in the transformation rule but that validation limits to record by record whereas I am looking for validation post all transformation.

Thanks!