At this point Dimension ahs no animation support, so no, you have to start over from scratch. the rest will totally depend on what you actually have to create. The video you linked features a bunch of conventional 3D animation, which has exactly zero to do with what you would do in AE. Sure, things liek the scroolling background could be faked easily, but you still need to model the 3D objects first and set up the scen, which as a minor would mean spending a good bunch of time in the Cinema 4D Lite version that comes with CC. Beyond that you would realyl have to be much more specific, but honestly if I may be so bold: If you have no prior experience with this and this is a critical project perhaps consider handing it off to someone else. It's too easy to botch this up and could end up embarassing you and your company...
Mylenium