How Can I Create A Rollup Field That Has A Rollup Field In It

Hi.  Here is my situation.  I have a Rollup Field on the Opportunity entity called "Total Costs" which is the sum of the various costs associated with that Opportunity which is in an associated Costs entity.  That works without issue.

Now what I want to create a Rollup Field on the Account entity for all costs for all Opportunities associated with that Account.

If I try to create an Account Rollup Field I can't include an Opportunity rollup field in it's definition.

I tried creating a standard currency field called "Total Costs (non rollup)" on the Opportunity entity where I then created a Business Rule to put the value of the Total Costs rollup field into it.  That field does not populate.

Any suggestions on how I can do what I want to do?

Thanks.


Rick Bellefond
RB Data Services
www.rbdata.com