Take half of the peeled and cored pineapple and chop it finely. Thinly slice the other half. Stir the lemon juice and sugar together in a large punch bowl until the sugar is dissolved. Add the chopped pineapple, Champagne, white wine, Cointreau, brandy, and club soda. Stir well. Add 1 large block of ice and garnish with the sliced pineapple and the strawberries.