Generally speaking, IDL has three ways to read an Excel data file, two of which are documented with examples. The most thorough way is probably NOT documented with examples. It would require you, the programmer, to learn the COM interface methods for Excel. These could then be used with IDL's COM interface, which you can read about in IDL's Online Help's Content tab page at 'Programmer's Guides->IDL Connectivity Bridges->Part I: Importing into IDL->Using COM Objects in IDL'. COM is a complicated interface, I should warn.

A second way to interface IDL with Excel would require Microsoft Visual Studio (or one of its subcomponents). An example, using Visual Basic, is provided in IDL Online Help's Contents tab page at 'Programmer's Guides->IDL Connectivity Bridges->Part I: Importing into IDL->Using ActiveX Controls in IDL->Example: Spreadsheet Control'.

Finally, although this interface is not officially supported, IDL Dataminer - at least in years past - has had the ability to interface with Excel - ***just for reading*** - with the approach described in ITT Visual Information Solutions Tech Tip #3319 ("Using IDL Dataminer to Access Microsoft Excel® Spreadsheets")

This approach requires acquiring an additional license for the IDL Dataminer "Add-On Module".

James Jones