Are you using the camera for animation or director's view camera? Only the camera that you can actually see as an object (blue pyramid) can be animated. As others have said set this camera to track your object (in fact there's a tutorial on the Bryce 4 CD for this) then set your time scrubber to a time (making sure auto key is on or remeber to set a keyframe) then move the camera to where you want it for that time, move scrubber again then move camera again, repeat until you have the motion you want. Preview then adjust the trajectory as needed. Bryce 4 has a .pdf manual with this tutorial in it for animating the camera, I don't have the Bryce 5 update but it should have something similar on the disk.