Yeah, there's no easy way to set up pathing unless there is NOTHING else happening in the demo.
For instance, if you have
0 CAM 1 0 0
5000 CAM 100 0 0
You'll get the camera smoothly moving across the map. BUT... you can't look at this like you would with keyframing in an animation program, because each object doesn't get its own animation timeline.
If you wanted a character running AND the camera chasing, logically you'd do this (MOV's removed for simplicity)...
0 1 POS 5 0 0
0 CAM POS 1 0 0
5000 CAM POS 100 0 0
0 1 POS 105 0 0
But you'll get undesired results. Because the second command for the character to move doesn't happen until AFTER the camera has moved, he'll just sit there and then teleport until after the camera movement. This is why demos have countless little movement ticks all meshed together looking like one huge mess.
Zloth's Demo Editor was meant to make it possible to create complex sequences and generate all the movement ticks based on setting keyframes, but it's sadly unfinished, glitchy, and hasn't been updated since around Issue 12.
There is one way I've figured out.
Create a new demo in Balshor's demo editor (I still have the program is anyone needs it) that is completely blank.
Make an new entity that will be the entity you want to have moving around in the demo (if the camera, this needs to be done twice, once for the Camera itself and once for the player toon).
Figure out your timing for your movements.
Then open the dome you want to have the moving object in.
click on "Import commands" and select the demo you made the movements in. It will import the commands and line items from it into the other demo.
Click "Resort" so everything gets sorted according to time code. The editor does a lot of the work for you leaving you with just a little clean up and fine tuning.
Not perfect, but markedly better then hard coding 500 separate POS and PYR changes.