The image above explains this better than any text. All cameras are 5 feet from the object and all cameras are taking the same shot. All have F set to 2.8. The blue number shows the actual focal length of the lens for each camera (so each camera frame the subject the same way)

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Some people think that the major technical difference between shooting video and shooting 35mm film is a progressive scan or 24fps. But that's not true, the most visible and obvious difference is shallow/deep DOF. If our scene is a close-up of person in front of a building, video will have most of the scene in good focus. 35mm film will show face in sharp focus and the building behind will be blurred.

This is also called selective focus and it is used by film makers to keep attention of the viewers on the main subject.

As you can see the difference in the above cameras is the size of CCD chip or film frame, also called a target size.

You can simulate selective focus a little, by pushing your camera back and zoom in. Many people would think that changing focal length will change the DOF - but that's wrong! The DOF will stay in fact the same (see image below). A zooming shortens the distances and that apply for DOF as well. But the image will also appear loosing its depth and looking flat.

On the image above we use same three cameras, all f/2.8 and each moved further back and zoomed-in so the subject appear the same on each viewfinder. The DOF doesn't change, because it doesn't depend on the focal-length (opposite what many people think). It depends only on F-stop (aperture) and that stays the same. However, thanks to the perspective, longer distance from object also virtually shortens the DOF. Zooming-in may look like it produced shallower DOF but any other distances are shortened as well so the image is loosing its depth.

What is the bottom line?
You can never achieve DOF of 35mm camera with a video camera unless you are able to change the target size (the size of CCD chip).

Changing target size.
Here is the question: How to change the target size of your video camera? Obviously you are not going to replace CCD. But there is a trick that comes from telecine devices. Such device is used to transfer the film to video. We will simply skip the film part and combine the telecine directly with the 35mm lens.

Lets the 35mm lens capture its image and project it to a 35mm target size. Then we will capture this projected image with our video camera in macro mode. The projected 35 mm image will have all the DOF characteristics of a 35mm camera. Our Video camera is a mere telecine device to record this projection.

Will this work?
Yes, of course, many devices works on this principle. We need something like a ground glass to project the image so we can capture it from the other side by our video camera.
The ground glass. At the 35mm frame size, a ground glass will more or less show its grain unless we can get some space-age superfine ground glass. Here comes a rescue again from a optometry laboratory devices that use ground glass for projection - we need to shake or rotate the glass somehow so the grain will become invisible to our camera.

Upside down issue.
One biggest trouble with this setup is that the image projected on the ground glass is upside down. Of course, every photo or video lens project the image upside down, just the electronics in the camera will make it flip. But now we have 2 lenses - the 35 mm and the camera lens so the image is also recorded upside down. And because we are capturing the projection from back, it is also horizontally reversed. Well, we can't have everything these days. You can either tun the camera upside down and the image will be just horizontally flipped (and you may even make a few friends using the camera like that) or simply swallow it and turn everything the right way in post-production.
To turn the image the right way optically before the camera captures it would be troublesome You need to use a mirror to turn flip it vertically and then pentaprism or pentamirror to flip it horizontally. This is out of the reach of most home-improvement guys. Especially that these things are not easy to find in VAL-MART or Home Depot.

So for our design we will simply make it flip at post-production. The easiest way is in fact to forget the flipping right now and add a small hood and a mirror to the LCD screen of the camera so we see the image correctly during shooting.