I found a solution that works fine for me. It's probably something most of you out there already know, but I want to share it here in case it might help somebody else.
After some forum search (not too much, that's true) there turned up Hot Potatoes. So I gave it a try, and nothing easier!!
1. Just create your hot potatoes activity. In my case it was a text my students have to read. No questions at the moment, I'm just interested in the time they take to read that text (measure reading speed)
2. Create the web page from Hot Potatoes "File" menu.
3. Upload the resulting htm file to the course files directory
4. Add a Hot Potatoes Quiz.
5. For the activity name select the "path to file" and then select the activity from the button "Choose or upload a file"
6. When the teacher clicks on "Reports", there will be the Hot Potatoes Quiz. Click on the quiz name and it will show a list with all the students' attempts, including score (if relevant) and time used for the activity.
7. The upper part of the page offers a form to download results in a choice of formats.