Using a video file during a webcast presentation may not be possible as due to internet bandwidth, will not lead to a good experience for all members of your audience. Playing an audio file may be a good alternative solution.
You could have a quote or one minutes story pre-recorded of someone and then play this file during your webcast presentation. Showing a picture of the person speaking and maybe some other relevant information / graphs / diagrams / pictures on screen may substitute the audio file. It is not a video but may have a similar impact and could work to allow for a good experience for all team members.