Preheat the oven to 350 degrees F. Use a medium bowl, and mix the flour and sugar.
Cut in the margarine with a pastry blender or use fork until the mixture resembles coarse meal. Press into an ungreased 9-inch square pan.
Bake 13 to 15 minutes, or until it is light brown. Use a mixing bowl, and beat together the eggs, brown sugar, 2 tablespoons lemon juice, and 1 teaspoon lemon rind until well combined and light.
Spread over the baked crust. In the oven bake for 20 minutes longer, or until the top is browned and puffed. Use a small bowl, and combine together the remaining 2 tablespoons of lemon juice, 1 teaspoon lemon rind, and the confectioners sugar.
Spread on the baked sours while warm. Let cool, and slice into squares.