Bigbluebutton - Display External link as an iframe

We're looking for a little customization on our Bigbluebutton installation (video conference system). We have been using this video conference service from a third party and would like to start using our own installation; however, we lack one important feature in our installation: the possibility to display an external url as an iframe on Bigbluebutton. This feature is supposed to behave like the "Share an external video feature" on Bigbluebutton. We use bigbluebutton for educational purposes, and displaying an interactive activity or game in iframe allows us to engage students in an interesting way in their online lessons.