You can refer to the contents of cells in another workbook by creating an external reference. An external reference (also called a link) is a reference to a cell or range on a worksheet in another Excel workbook, or a reference to a defined name in another workbook. You can refer to the specific cell range, a defined name for the cell range, or define a name for the external reference.
To access an external file, you need to read it using whatever method is appropriate. For instance you may use the XmlDocumentComponent for instance to read an Xml file. If the file is in a standard location, you can access it directly with the path. However, if you are interested in sending as part of the project - just add it to your solution in Studio. To find it at runtime you need to use the simple process shown here: