when you use cl_showpos 1, it gives you 3 coordinate number in the top right. The numbers will constantly change if you move the camera around or your character. Once you stop moving your character and camera after a few seconds they change from battle pose to a rest pose. Once the character does that the 3 coordinates will stop jumping around. That is when you write down those coordinates and use setpos to move you back to that coordinate that you just copied down.
For example in irukul the coordinates for the main room where you battle irukul is 11578.18 453.53 94.78. So you would use setpos 11578.18 453.53 94.78 and it will take you to the main battle room.