You cannot do this in Encore, AFAIK - but I will have a look in case I am mistaken.
VideoCD uses MPEG encvoding but this is roughly where the similarity ends - VideoCD uses 44.1KHz audio, not 48KHz.
Commercial CD that have additional PC content are again different animals - the way these discs (which are called "CD-Extra" or "CD+") are normally created is in a multi-session CD creation tool. You create the audio content first, then when you write the disc you do not close or finalize the session but leave it open - then you go into CD-ROM mode and add the additional content, this time closing the session.
Such discs can be created quite easily in GEAR Pro Mastering Edition, or WaveLab. What OS are you running please?
You would need to prepare the content outside of the final authoring tool, and commercial CD can (and often do) use Director created content or Flash created content - the down side to Flash is that it will not work on a Mac. You can also create the videos in Quicktime Pro - simply load into it your regular full scale version, and then export for web - this will create 3 separate versions at varying quality (Smart Phone, iPhone & iPad are the references although all will work on your CD-Extra disc.
Please post back if you need more assistance