Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Icon File / ID
ID_BASELIST_ICON_FILE
Parameter: Icon Color
ID_BASELIST_ICON_COLORIZE_MODE
Parameter: Color
ID_BASELIST_ICON_COLOR
Parameter: ID_BASELIST_ICON_PRESET_BUTTONS
ID_BASELIST_ICON_PRESET_BUTTONS
Parameter: Name
ID_BASELIST_NAME
Parameter: Layer
ID_LAYER_LINK