BCGControlBar Pro for MFC
void CBCGPColorBar::EnableAutomaticButton ( LPCTSTR  lpszLabel,
COLORREF  colorAutomatic,
BOOL  bEnable = TRUE 

Shows or hides the automatic button

Call this member function to enable (show) or disable (hide) automatic button. The button is disabled when the lpszLabel parameter is set to NULL and/or bEnable parameter is set to FALSE.

lpszLabelSpecifies the automatic button label
colorAutomaticSpecified an automatic button color
bEnableTRUE - show an automatic button