To prepare crust, combine crushed cookies, margarine, and sugar in a mixing bowl. Press mixture firmly in a 9" pie pan. Chill one hour, or until firm. Or, bake in a 350 oven for ten minutes or until lightly browned. Cool on rack before filling. To prepare filling, completely dissolve gelatin powder in boiling water. Combine cold water and ice cubes to make 1 1/4 cups. Add to gelatin mixture, stirring until slightly thickened. Remove any unmelted ice cubes. Fold peppermint extract into whipped topping. Using wire whisk, blend whipped topping mixture into gelatin mixture. Then, whip until smooth. Chill until mixture mounds. Spoon into crust. Chill two hours, or until set.