How do I get Microsoft Excel 2007 as an add on to Outlook 2007

No.

However, there are free versions of Excel (later versions), such as the web version and the UWP version.

"How do I get this? Links?"

Go to msn.com and sign in. Click the Office tab at top

Halfway down page that opens, click Office program of your choice (may not contain full features like template packages but OK for 95% of users). Your work is saved in OneDrive from where you can sync to all your devices or copy to This PC folder. You can only change documents online, of course.

N7AS said:

That would not work for me as I have to have Excel installed on my PC. I program radios and to export from one radio and import to another, that would not work as it's online.

Do you need to write macros for this? If so, that's one of the features missing from the free versions.

Does it have to be Excel? Would LibreOffice or Open Office do the job?

N7AS said:

I don't have to write macros. OpenOffice or LibreOffice will not as I have both. It HAS to be Microsoft Excel and write/read .xls files.

Just because it's online doesn't mean you can't read and write excel files. You can write the files to OneDrive and it will sync locally, or you can download the file.

Or, as I said, you use the UWP version (go to the store and download it).

N7AS said:

OpenOffice or LibreOffice will not as I have both. It HAS to be Microsoft Excel and write/read .xls files.

Even though LibreOffice can read/write 'Microsoft Excel 97/2000/XP/2003 (.xls) (*.xls)' format?