Get raw joystick (axes) input

Hello,

I'm currently working on a game in Unity, and I'm creating a custom input manager, we're developing this because Unity's input manager is a bit limited. Now I would like to get raw joystick inputs. For example, is there a way to get raw axes input from the joystick based on a controller ID. You can manually add a joystick and select the axes in Unity's input manager, but that's not what I want, as I said I would like to get the axes from a specific controller. Is there any possible way to achieve this? Also, about the buttons on the controller it self, it is possible to check whether buttons are pressed or not by using the Input.GetKeyDown() method, then you can use KeyCode.Joystick1Button0 for example as key ID. Also this is a bit limited, it only goes up to 4 joysticks and also isn't really useful in coding. So also for these buttons, is there a function available like GetJoystickButtonDown(int joystickId, int buttonId); or similar?

I hope I explained it clear and correctly.

Thanks in advance,

Tim Visée