Thanks for getting in touch!
This behaviour is possible if you manipulate your datasource.
When you reload your chart you would need to add a seperate SChartColumnSeries, one for your old data (0-5) and a one for your new data (5-8).
Then disable animations on the series that would show your old data and enable animations on the series that shows your new data.
Finally, make sure the series representing your old and new data have been set the same "stackIndex" value.
This should produce the effect you've described.
Let me know if you have any issues.