Hi Kenneth,
Thanks for using Syncfusion Products.
You can able to achieve your requirement using ChartRegion Events in Chart Control. The ChartRegionMouseXXX events can be handled to provide any custom actions.
Please take a look at the attached sample.
http://websamples.syncfusion.com/samples/Chart.Windows/F61267/main.htmThe above sample does the selection by handling the ChartRegionMouseDown and ChartRegionMouseUp events.
Let me know if you have any more queries.
Regards,
Rashidha.