I can tell you how to add a dark spot and taylor it to the shape you want - I can tell you how to beam light through an object or text. I can tell you how to add shadow to text. Spot shadow is a little vague to me. Would you care to elaborate on what you would like to do?
If you go to the Vaast web site Douglas Spotted Eagle (or Spot as he is known here) and other experts have a ton of tutorials to help you. Beaming light involves using the light rays fx - in the example I had in mind through a mask and compositing the thing together. Beaming a light to a persons face would be a compositing challenge because of the key framing involved in which the target may be moving which would mean both the light and the mask would have to move as well - unless the angle was fixed in which case track motion could be used. It would be a lot easier to simply put a highlight on your subject without the beam. Look at Spot's tutorial for a title flare for an introduction into using light rays.
Thanks for your responses. I forgot I had posted this up here. I'm going through the tutorials on vasst, looking for the right one. What I'm basically aiming to do is to freeze the video for a second or two, and lower the brightness of the entire frame except for a certain "spot," thus creating a highlighting effect around a focal point.
If that's all you want to do then the easiest thing would be to use a mask with the desired shape and make it transparent. Check the masking topic in the docs for examples.
(Personally, I don't understand why the built-in cookie cutter masks don't have an alpha control... worth a suggestion I guess)