how can i add 6 seconds of video to the start of an existing video?

Sorry first to ask questions because so much wrong terminology is used. What do you mean by 'video'? Is that a real video inserted as event video or mult-synchronized video in a cptx-project? Or are you talking about a cpvc-project which leads only to a video? Or are you talking about an interactive cptx-project? Which version of Captivate do you use, please? Exact version number is best.