Office 2003 programs support XML in ways that make sense for them.
Several of the programs in the Microsoft Office Professional Edition 2003 support XML. Each program furnishes XML tools that coincide with the nature of the program itself. The earlier practice showed how Word 2003 allows you to save files as XML. You can also attach schemas and transforms to your Word 2003 documents.
Excel 2003, on the other hand, uses the concept of a map for working with XML. You create a map by linking the cells in a worksheet to elements in a schema. You can't save a workbook as XML unless you first create a map (which you'll see how to do in the practice session for this lesson).
The best way to learn how an Office 2003 program supports XML is to open Help for that program and search on "XML" for more information.
As for XML schemas, transforms, or data from other suppliers, Microsoft Office Professional Edition 2003 programs are ready to work with those.