In a previous thread, I described a method for getting your report totals in a portal. With the data displayed in a portal, you can place the portal on the left and the chart based ont he portal on the right all within the same layout part--the body.
I'm actually working on that now. I was hitting a wall with the portal method so I tried the report first.
I just got the portal working. The problem seems to have been something to do with a calculation field added to an ODBC linked table not matching correctly. Once I imported the data to a local table and used an auto-enter lookup field instead the method you described in the other thread worked.