BCGControlBar Pro for MFC
virtual int CBCGPToolBar::InsertSeparator ( INT_PTR  iInsertAt = -1)

Insets the separator at a specified position.

The index of the inserted separator; -1 if it was the first item in the toolbar's list of buttons.

Call this function to insert a new separator between the existing buttons. If iInserAt is -1, the separator is added at the end of the internal list of the toolbar buttons.

You can't add separator to the empty toolbar.

iInsertAtSpecifies the zero-based position to insert the separator at.