THE PILOT REPORTED THAT AT ABOUT 200 FT (AGL) ON INITIAL CLIMB FROM TAKEOFF, A COMPLETE POWER LOSS WAS EXPERIENCED ON THE LEFT ENGINE. HE STATED THE LEFT PROPELLER WAS FEATHERED, BUT THE AIRCRAFT WOULD NOT HOLD ALTITUDE AT RECOMMENDED SINGLE-ENGINE SPEED DURING A GRADUAL TURN BACK TO THE AIRPORT, NECESSITATING A FORCED LANDING ATTEMPT ON A PAVED ROAD. AFTER TOUCHDOWN, THE AIRCRAFT DEPARTED THE HARD SURFACE, CROSSED AN EMBANKMENT AND CAME TO REST IN A FIELD. INVESTIGATION REVEALED NO MALFUNCTION OR FAILURE IN THE LEFT ENGINE. INVESTIGATION FURTHER FOUND THE LEFT PROP CONTROL IN HIGH PITCH VS FEATHER AND THE FUEL SELECTORS ON AUXILIARY TANKS, CONTRARY TO AIRCRAFT FLIGHT MANUAL INSTRUCTIONS. THE MANUFACTURER STATES THAT TAKEOFF ON AUX TANKS WITH 10 GALS CAN UNPORT THE ENGINE FEED PORT. THE PILOT STATED HE SWITCHED BOTH ENGINES TO AUX TANKS DURING ATTEMPT TO RECOVER POWER.