I've been working on a small software to import/export/create/edit quiz-questions for Moodle, Blackboard, and D2L. It's still very much work-in-progress and it's my first time programming in C#, but maybe you'll find it useful.
Use at your own risk
If you find any bugs or if you have any feedback whatsoever, please let me know.
Here's a short video explaining how it works:
The file (Windows only, sorry): https://www.dropbox.com/s/6fq9eakzxndgf5d/quizmaker11.exe?dl=0