Drain cherries; pour into unbaked pie shell. Cream margarine, flour, and sugar replacement. Add egg yolks and beat until smooth. Add evaporated milk and vanilla extract. Pour over cherries. Bake at 450°F for 10 minutes. Reduce heat. Bake at 350F for 30 minutes. Whip egg whites until soft peaks form. Add granulated sugar replacement; whip until thick and stiff. Top pie filling with meringue, carefully sealing edges. Bake at 350°F for 12-15 minutes, or until delicately brown.