You need to think about what it is you want to do. Excel can read and write several types of files, two of which use an Excel-specific file structure and are characterized by the extensions .xls and .xlsx. If you want LabVIEW to read these types of files, you need to use the LabVIEW Report Generation Toolkit (which can "talk to" Excel and get it to "do the dirty work" of managing the file format) or a third-party add-on that knows how to parse the file. Note that the native Excel file has such features as Colored Cells, Borders, Graphs, etc.
On the other hand, if you have text data in a 2D format, with columns separated by <Tab> or some other character, such as a comma, and with rows separated by <NewLine>, then this text file can be read and parsed as a 2D array of String or Numeric data without needed Excel, just by using LabVIEW's Read/Write Delimited Spreadsheet File functions. [The name of this function changed a few years ago when NI added an extra pair of terminals at the bottom for the Error Line].
Note that earlier answers to your question say more-or-less the same thing I've said -- I'm just wearing my "Professor" hat and trying to wrap it up in a single package ...
Bob Schor
