I'm a little bit confused on what you want to do. But first, let me digress a minute:
- A CSV file is a "Comma-separated Values" file, a plain text file that uses a delimiter (often a comma, hence the name, but other characters, such as a <tab>, the LabVIEW default, are also commonly used, particularly when the data "being separated" contains commas (like numeric string representations in Europe).
- A CSV file has nothing to do with Microsoft Excel. However, Microsoft decided to associate an "Excel-like" icon with this file type. Excel can "recognize" this Text file, can open it, and can allow you to use Excel to examine and modify the data. However, any "Excel-specific" changes you make (like formatting) won't be saved when you close the file unless to save it as a .XLS or .XLSX file.
So here's my question: what do you really want to do? Do you have an Excel (.xlsx) file? Does it have any Excel-specific "features" (such as formatting, column widths, coloring, graphs, etc.)? What do you really want to do with it?
You mention that the Excel file has multiple Sheets, and that you want to process all (?) or some (?) of them (this is not clear). You seem to be hung up on how to handle the multiple Sheets, and seem to be looking for a generalization of the CSV format that would allow you to have a single File with multiple CSV-formatted data inside it. This is sounding already too complicated.
So here are some suggestions. Let's assume your Excel file is called My Data.xlsx, and it has four sheets, Run 1, Run 2, Run 3, and Run 4. Note that I'm assuming you have the Report Generation Toolkit, which allows you to read and write Excel (.xlsx) files.
- Create a folder called My Data. Open My Data.xlsx. In a While Loop, open each Sheet and read the data. Use Write to Delimited Spreadsheet to create a CSV file named for the WorkSheet (i.e. the first file will be in \My Data\Run 1.csv).
- Instead of fussing with CSV files, just use the Excel File. Use the RGT to open My Data.xlsx. In a While Loop, open each Sheet, read the data, extract what you need, make whatever changes to the file you might want (you didn't mention doing this, but you certainly could, if it was useful), and if it makes sense to do so, save the extracted data using some naming convention so you know from which Sheet the data came. Much simpler, but it may not be what you really want to do ...
Bob Schor
P.S. -- did you realize that the RGT can be used to read Excel files, as well as write them?
