ON AN IFR BUSINESS/TRAINING FLT, THE ATP PLT MADE AN UNSCHEDULED FUEL STOP. ON A PRACTICE ILS APCH TO RWY 3, CIRCLING TO LAND RWY 21, THE ACFT YAWED HARD RT AND THE PLT LOST DIRECTIONAL CONTROL. THE PLT SAID IT SOUNDED AND FELT LIKE THE RT ENGINE HAD LOST POWER. THE PLT SELECTED GEAR UP AND REDUCED THE THROTTLES AND MIXTURE CONTROLS. THE PLT SAID THAT WITH THE GEAR DOWN, FLAPS AT 15 DEG, AND THE RIGHT PROPELLER NOT FEATHERED, THE AIRPLANE WOULD NOT CLIMB. HE ELECTED TO LAND BETWEEN RWY 3 AND 8, ON A DIRT AREA. DURING LANDING, THE ACFT TURNED 180 DEG AND SLID 270 FT BEFORE COMING TO REST. A POST ACCIDENT INVESTIGATION BY AN FAA INSPECTOR REVEALED THAT THE RT FUEL SELECTOR WAS IN THE RT AUXILIARY FUEL TANK POSITION. THE RT ENGINE FUEL LINES CONTAINED A FEW DROPS OF FUEL. BOTH AUX TANKS WERE EMPTY AND NO FUEL WAS FOUND IN THE DETACHED RIGHT MAIN FUEL TANK.