Thanks for the quick response.
I am looking something different. The example provided by you helps me to add image once I have downloaded it from the URL and I have it in my physical drive.
But in my case I will be getting the URL generated at run time and for each row it will differ and while exporting I need to contact to respective URL and then fetch the image and add it back to the workbook. It will be great if you could get me some working solution for my case.
Actually my requirement is to draw a sparkline for given data sets. If their is any other way to get the same, do please let me know.