BCGControlBar Pro for MFC
BOOL CBCGPGridCtrl::SetHeaderImageList ( UINT  nResID,
int  cxImage = 16,
COLORREF  clrTransparent = RGB(255, 0, 255),
BOOL  bAutoScale = TRUE 

Sets the image list associated with the header.

nResIDSpecifies the image list resource ID.
cxImageSpecifies the image width.
clrTransparentSpecifies a transparent color (for 24bpp or less images).
bAutoScaleSpecifies whether image list should be automatically scaled according to current DPI.
TRUE if it succeeds, FALSE if it fails.