Put flour, oatmeal and baking powder into a bowl. Rub in margarine and sugar until it resembles fine breadcrumbs. Add beaten egg and milk and mix by hand until it forms a firm dough. Put onto a floured board and roll out until 1″ thick. Cut scones with a 2″ cutter. Place on a floured baking sheet and put into a medium oven (220°C/425°F/gas 7) for 15 minutes, or until golden brown.