Ah ok. There are two ways to get the "schema" into Excel.
Option 1) The easiest is to just open your form, save an empty data file. Then in Excel instead of mapping to an XSD you can also map to an XML file. It will interpret the XSD schema from the sample XML file you created from InfoPath.
Option 2) To get the actual XSD from InfoPath, in InfoPath designer, select File::Save as Source files or Extract Source Files (depending on the version you have). Then in that folder you will find an XSD file which corresponds to your form's main data source. Point Excel to that file.
Note, the second method is required if you have any optional or repeating sections because the empty sample file you save from InfoPath may not include those in a way that Excel can interpret just from an empty sample file.
Shiraz Cupala / Microsoft InfoPath MVPQdabra® Software / Streamline data gathering to turn process into knowledge