Unknown informaiton:
Macintosh model.
System / MacOS X version.
Handycam model (a web page link or links, would be nice).

Briefly, 'Visual Basic' is not native to the Macintosh platform. Well, except for the waterdown version ('Visual Basic for Applications') incorporated within Microsoft Office for the Mac.
Yes, you can program in BASIC and C; as well as, C++, Java, JavaScript, Perl, and Python - to name several, on a Mac runnning either System (9.2.2 or earlier) or MacOS X (10.0.0 - 10.4.2).

Surely, you cannot expect explicit assistance, by not providing any specific information.
In addition, you cannot connect a digital video camera through your DVI port. DVI port is "out-only" meaning you can't get information into your computer via the DVI port -- it's only good for getting information (graphics display) out of your computer.

You can, if your digital video camera has one, connect the camera via FireWire to the computer.