BCGControlBar Pro for MFC
void CBCGPToolBar::EnableCustomizeButton ( BOOL  bEnable,
UINT  uiCustomizeCmd,
const CString &  strCustomizeText,
BOOL  bQuickCustomize = TRUE 

Enables or disables an additional "customize" button on the toolbar.

If uiCustomizeCmd is -1, then the "customize" button is displayed only when several toolbar buttons don't fit the toolbar area. In this case the button displays a double-left arrow ("chevron"), indicating there are more buttons to show.

If uiCustomizeCmd specifies a valid menu command ID, the "customize" button becomes permanent, displays a small down arrow and opens a dropdown menu containing a single menu item with strCustomizeText label. If the toolbar can't display several buttons, these buttons are added dynamically before the item specified by uiCustomizeCmd and "chevron" is displayed along with the down arrow.

bEnableEnables or disables the "customize" button.
uiCustomizeCmdSpecifies a menu command ID, which is attached to the "customize" button
strCustomizeTextCustomize button text.
bQuickCustomizeEnables or disables the "quick customization".