Is it possible to map Alt + LMB to MMB + LMB??

building large scenes requires lots of clicking and moving around through the scene and I'm very used to LMB + MMB to rotate the scene around a specific object (because of different 3D softwares). But unity has rotate about object mapped to Alt + LMB. Is there a way where i can map it differently or just add that on top of the already existing Alt + LMB? I tried and failed using an editor script and also just trying to using [ExecuteInEditMode] and popping in GetMouseButtonDown(0) & GetMouseButtonDown(2) into a script attached to a game object. Neither worked. Any thoughts?

 

any takers?