BCGSuite for MFC
BCGCBPRODLLEXPORT UINT BCGM_ON_CHART_MOUSE_UP

The framework sends the BCGM_ON_CHART_MOUSE_UP message when the chart visual object receives a mouse up down notification.

Parameters
wParamID of chart visual object.
lParama pointer to a BCGPChartHitInfo structure.
Returns
TRUE - disable further mouse up processing. In this case zoom /pan/selection will not occur (if enabled).

You should process this message to implement interactive charts.