Hi Pierre!
Thanks for reaching out. Creating such a relationship is possible, but would unfortunately require some significant custom coding to implement 🙁
So to implement those sorts of features and that custom relationship, you would have to write extensive custom code yourself or hire a professional developer to do it for you. We have a list of great developers here → http://m.tri.be/18k1 (and have no affiliation with any of these folks—they’re simply some well-respected names in the community that we’ve compiled to share in situations like this one).
I hope this information is helpful to know — please let me know if so and if there are any other issues or questions I can try to help with.
Thanks!
George