Bring 1 can chicken broth to a boil in a small saucepan; remove from heat. Add mushrooms; let stand 30 minutes. Drain well, reserving mushroom liquid. Coarsely chop mushrooms; set aside. Melt margarine in a Dutch oven over medium heat. Add onion, carrot, and celery; saute 5 minutes. Add remaining 2 cans chicken broth, reserved mushroom liquid, and mushrooms; bring to a boil. Cover, reduce heat, and simmer 10 minutes. Remove from heat. Place half of mushroom mixture in container of an electric blender; cover and process until smooth. Return mixture to pan; add rice and next 4 ingredients. Cover and cook over medium-low heat 10 minutes. Place flour in a bowl. Gradually add milk, stirring with a wire whisk until blended; add to soup. Cook, uncovered, over medium heat 10 minutes or until thickened, stirring occasionally. Yield: 1-1/2 quarts (serving size: 1 cup). Calories 152 (18% from fat), protein 6.1 g, Fat 3 g (sat 0.8 g, Mono 1.1 g, Poly 0.7g), Carb 25.3 g, Fiber 2.2g, Chol 2 mg, iron 1.4 mg, Sodium 278 mg, calcium 40 mg soup 62