Use the Hotspot event to modify most aspects of the Hotspot Map's Point Regions. The event should be manually added to the WebForm.
public SeriesHotspotEventHandler  GetHTMLMap

Example

//WebForm OnInit event.
override protected void OnInit(EventArgs e)
{

  ((Steema.TeeChart.Tools.Hotspot)(WebChart1.Chart.Tools[0])).GetHTMLMap += 
  new Steema.TeeChart.Tools.SeriesHotspotEventHandler(this.hotspot2_GetHTMLMap);

  base.OnInit(e);
}

See Also

SeriesHotspot Class | SeriesHotspot Members | Steema.TeeChart.Tools Namespace