There is no support for multiple webcams in Presenter Video Express. Can you elaborate a bit more on your exact need?
You can always have all the presenters captured by a single webcam, or do additional recordings with multiple presenters if that works. Please let me know.
I have not tried in Presenter 10 but in version 9 below worked.
if you hook up different web cam models (meaning not the same model x 2 or x 3 but totally different models) you can use multiple cameras and "switch" between them by using the pause function on the keyboard while recording videos. An example. Use 2-3 web cams that are all HD cams but different models (Logitech 920 HD is a good choice for this plus one or two other Logitech HD models). You can then record with say your main camera pointed at you, pause the recording, choose a camera that is over your shoulder for a "see what I am seeing on my monitor" as an example and then switch again to a third camera for a profile view of yourself.