For simple diary stuff I recommend either ‘DAFNE Online’ or ‘Diabetes Diary’.
Both free and both allow you to download to CSV.
The DAFNE one does it automatically and uploads to it’s website but limits entries to 15 per day.
The Diary needs you to manually export.
The best way I’ve found to get the professionals to like your data is to display it in a way they are used to from traditional paper layouts although that can be a bit fiddly if you’re not too comfortable with Excel.
Hope that’s useful.