AnalyticalTable: Aggregate property in the analytical table columns

[pppwr7]

Hi Colleagues,
I see that the analytical table columns have property like aggregate, Aggregated and aggregateValue. I dont find any example on how to use this property. Could anybody please help me with an example about this. I have a requirement to show the total of the quantities at the bottom of the table column. This total is brought in via another field and is not supposed to be caluclated out of the currently loaded rows. Please let me know if such feature is available currently.