Isolate last record of history

Hi, I'm a new member and new with Crystal reports. I am using Crystal 10.

I am reporting on data in a "mirror" database. There is a production database that downloads into the mirror database each night. The data is patient account data. Each account can have several "buckets", Pre-billed; Primary Claim; Secondary Claim, etc.

I am reporting on three tables:
The first is the Account table
The second is the current bucket state
The third is the bucket history

In the bucket history table any given bucket can have thousands of lines. A new line is created for the bucket anytime something happens to it.

I want to create a report that, at anytime during the month, I can isolate the state of the account buckets on a given date.

For example, today 12/06/05, I want to run a report for the end of the month. So I want to exclude bucket activity after 11/30/05 but select only the single latest activity of all buckets as of 11/30/05.

How would I isolate that last activity and exclude all previous activity?
Thanks
Steve