Thanks for your inquiry. I can suggest you two ways to achieve this using Aspose.Words.
You can try using bookmarks inside your document. Please see the following code example:
// Open the document.
Document doc = new Document("in.doc");
DocumentBuilder documentBuilder = new DocumentBuilder(doc);
// Go to bookmark
documentBuilder.MoveToBookmark("Image");
// Insert Image
documentBuilder.InsertImage("Test\img.jpg");
doc.Save("out.doc");
Or you can try using merge fields, in this case you will be able to use MergeImageField event handler to achieve what you need. Please see the following forum thread to learn how to do it during MailMerge: https://forum.aspose.com/t/84533
Best regards,
Thanks for additional information. Could you please attach your document and code here for testing? I will check the problem on my side and provide you more information.