You can also create an html representations of an Excel document that excel can load. The advantage of this approach over the Text:CSV format is that you get more control over the appearance of the spreadsheet. Column width, Fonts are controlable. You can also do formulas. The reason for doing this is to create Excel output from another program that is not excel.
Try this:
1. Create using Excel a simple version of the spreadsheet you want to produce. SaveAs 'html' if you open it with notepad you will see a text format that can be produced by a program.
2. Rename the file with an xls extention. When you open it Excel opens it just as if it were an excel file.
3. Create your file using the format you saw in step #1 substitute your own values.
Problems:
If you have data in more than one worksheet in your excel file the SaveAs 'html' produces a file, a folder with a bunch of other files. This makes things much more complicated. In my case I am trying to make email attachements the multi file version of this is not good.
Conclusion:
If you are creating something with just one worksheet or have a more robust way of distributing your result the html format works well.