Plugin data manager csv export

[filo91]

I was looking for a way to export my data (saved with forms) into a csv file and I found this archived:

Form plugin data output

I need to output the form plugin data in csv format (comma-separated), and always append new data to the file so only one file gets created. Any clues as to how would I go about doing this?

Here they say to create a file appending the data every time. Instead of doing this can we create a file on request with a template that takes the data and puts it comma separated in a csv file and then download that? It would be a nice feature to basically export something you can put in excel, for a client that would be really nice.