如何在Office文件中嵌入图像以用于自定义功能区

I am developing a custom ribbon extension for Excel, in which a control requires different custom images. I managed to use some images located in my filesystem, but I would like to embed these images inside the .xlsm file. Is it possible to do it and to reference them from the VBA code that updates the image of the control?I am developing a custom ribbon extension for E