Place crackers in a food processor; process until crumbly. Add sugar, margarine, and egg white; pulse 5 times or just until moist. Press crumb mixture into a 9-inch pie plate coated with cooking spray. Bake at 350° for 8 minutes, and cool on a wire rack 15 minutes. Freeze pie- crust 30 minutes.
Place an extra-large bowl in freezer. Remove yogurt and daiquiri concentrate from freezer; let stand at room temperature while crust is cooling.
Spoon yogurt into chilled extra-large bowl. Gently fold concentrate and rum into yogurt. Freeze 45 minutes or just until set but not solid. Spoon yogurt mixture into prepared crust; freeze until set. Cover with plastic wrap; freeze 6 hours or until firm.
Place the pie in refrigerator 30 minutes before serving to soften. Serve pie with Strawberry-Rum Sauce.