I'm nearly sure it's not. the Commander in Chief is a civilian role, not a military role. He is also immune to prosecution while sitting as President, so he would have to be impeached before anything like a trial could begin.

The House starts an impeachment, this is like an indictment. An official charge of a crime or offense.

The Senate judicates that charge and determines to remove from office or not.

Then and only then could criminal charges be brought. A sitting President cannot be charged with a crime.