Magnetic fields emerging in the solar atmosphere control the structure, dynamics and heating of the solar corona. Those fields remain essentially unattainable with present low corona instrumentation. We present the most direct way of magnetic field remote measurements in the internal corona, namely visible and infrared coronal emission lines magnetometry and we explain why Dome C should be investigated as a likely outstanding site for such observations. We develop a strategy towards a large aperture coronal magnetometer at Dome C in the context of the other main instrumental projects underway for solar physics.