UniGrid Export With Images

I have created a module that creates a unique barcode image for ordered items. I need to be able to export this as an Excel file and keep the images in place. When I finally got the barcode images in the UniGrid, I thought I was done; however, when I use the built-in export to xlsx, it removes the barcode images. Does anyone know how I could convince it to export those as images in the Excel file?

Here is the code creating the barcode images:

private object ugBarcodeOrders_ExternalDataBound(object sender, string sourceName, object parameter)
{
    switch (sourceName)
    {
        case "barcode_init":
            return "<img src=\"[path here ...]/GenerateBarcodeImage.aspx?d=[data, etc...]" />";
    }
    return parameter;
}

Thanks!