Lots of ways to do this… Why not just use a solid layer with alpha and convert it to a 3D shape? You could use the lightning plugin and set start-end points…even match them to nulls that follow your shapes. You could also do this with a 3rd party plug-in like Trapcode 3D stroke (you would still have to fake some of the 3D) or Particular…
What kind of ‘beam’ effect are you going for? Laser, partcile stream, dashed line (could use text characters on a motion path…)?