HFM Rule - Is it Possible to store a calc at a Parent Account?

Is it possible to write an HFM rule such that it stores the result at the Parent account level & <Entity Currency> value member?  Note that I do NOT want to store the amount in the <Parent Currency> member

For example, I have a Parent account with 3 base member children...

This is how the HFM account hierarchy adds up the children inherently:

Parent1     300

     Base1     100

     Base2     100

     Base2     100

This is what I want to accomplish:

Parent1     123

     Base1     100

     Base2     100

     Base2     100

In essence I want to ignore the 300 at the <entity Currency> and replace it with a calculation.

Any help would be much appreciated