Text 50,50,"Cam_x: "+EntityX(cam)+" Cam_y: "+EntityY(cam)+" Cam_z: "+EntityZ(cam)
Edit:
Use EntityX/Z/Y() commands to get the location of a entity...
otherwise, keep track of its position like so:
personx=0 persony=0 personz=0 PositionEntity person,personx,persony,personx
then print those veriables like so:
Text 50,50,personx
Hope i helped