How can I apply a position (and not a translation) to my camera related to an axis value

Hello,

I've been trying a lot of different ways to do this, reading the docs and tutorials and I still didn't managed it. I want my camera to move according to a joystick position, between UP (=1) and down (=1). But I don't want it to be translated according to the joystick value (althought that's what I get). I want the camera to move only when the joystick value changes.

When the joystick is =+1, the camera should be at a maximum position along Z axis. If the joysticks stays UP (=1), the camera should stay at this position. If the joysticks then gets 75% UP (=0,75), then the camera should go BACKWARDS to move to a position representing 75% of the distance between the initial position and the maximum position.

I don't know if you will get what my I mean.

Here is my actual code :

     public Vector3 Campositionworldinit;
     public Vector3 Campositionlocalinit;
     public Vector3 Campositionworldtarget;
     public Vector3 Campositionlocaltarget;
     public Vector3 Campositionlocaltarget2;
     public Vector3 Campositionworldactual;
 
 
     void Start()
     {
         Campositionworldinit = transform.position;
         Campositionlocalinit = transform.InverseTransformPoint(Campositionworldinit);
 
     }
 
 
     void Update()
     {
 
         Campositionworldactual = transform.position;
         Campositionlocaltarget = Campositionlocalinit;
         Campositionlocaltarget.z = Input.GetAxis("Joystick1X"); 
         Campositionlocaltarget2.z = Campositionlocaltarget.z - Campositionlocalinit.z;
         Campositionworldtarget = transform.TransformPoint(Campositionlocaltarget2);
         print("Campositionlocaltarget2.z" + Campositionlocaltarget2.z);
 
         transform.position = Campositionworldtarget;
 
     }
 }

Another weird thing ; when my joystick is on neutral position (=0), there is no printing for Campositionlocaltarget2.z is the console (which should be = 0). Only preceding values. Why ?

Thank you very much for your kind help.