BCGControlBar Pro for MFC
UINT BCGM_ON_GAUGE_CLICK

The message is sent to the owner of Gauge when the users clicks a Gauge.

Parameters
wParamcontains the control ID of the Gauge object.
lParamthe low-order word specifies the x-coordinate of the cursor. The high-order word specifies the y-coordinate of the cursor. The coordinates are the screen coordinates.
Returns
the return value is ignored.