Exclude specific customers from proport mechanism

Hi,

    There are three customers A,B,C under org ORG1, in this one customer C became invalid this month.Whenever there is an update happening at ORG1 level values are getting split for all three customers. Since the customer C became invalid the override value at ORG1 should split only to the customers A and C.What changes should i do in Demantra to achieve this?

Thanks in Advance,

VVM