BCGControlBar Pro for MFC
BOOL CBCGPLinearGaugeImpl::ValueToPoint ( double  dblValue,
CBCGPPoint point,
int  nScale = 0,
BOOL  bOffset = FALSE 
) const

Given a gauge value returns a point in client coordinates.

dblValueSpecifies a gauge value.
pointContains a point when the function returns.
nScaleSpecifies a scale index.
bOffsetSpecifies whether a scroll offset should be used.