Open the data source file.
At the beginning of the data field name, type an “at” symbol (@) to insert text or paths that refer to image files.
The @ symbol is required only in the first line; subsequent lines should include the image paths. Paths, which are case-sensitive, must follow the naming conventions of the operating system in which they’re stored.
If you get an error message when you type the @ symbol at the beginning of the field, type an apostrophe (') before the @ symbol (such as '@Photos) to validate the function. Some applications, such as Microsoft Excel, reserve the @ symbol for functions.