BCGControlBar Pro for MFC
BOOL CBCGPComboBox::SetImageList ( HIMAGELIST  hImageList,
int  nVertMargin = 2,
BOOL  bDisplayIconLeftOfEditBox = FALSE 

Sets image list.

hImageListList of images.
nVertMarginThe image vertical margin.
bDisplayIconLeftOfEditBoxIf this parameter is TRUE and selected combobox item has icon, the icon will be displayed on left side (CBS_DROPDOWN style).
TRUE if it succeeds, FALSE if it fails.