A "Which comes first? Chicken or the Egg?" question...

Parent Table INVT
Child table Stock (has the field .Store and .Qty)

I have a data aware view (gtAutomatic) where I want to put a filter where the user can dictate to get only INVT records with total .Qty of child Stock records matching to the filter criteria.

Is this possible? Or the only way is to have a non-data aware gird* (onmanualload goes through each INVT then go through each child STOCK records)?

thanks in advance..