In a mixing bowl, cream together butter and sugar for 2 minutes or until light and fluffy. Add eggs; mix well. Gradually add milk and vanilla; mix well. In a small bowl, combine flour, baking powder, baking soda and salt; add to the creamed mixture. Fold in coconut. Cover and refrigerate for 2 to 4 hours. Shape into 1 inch balls. Place 2 inches apart on greased cookie sheets; flatten with fingers into 2-1/2 inch x 1 inch oblong shapes. Press lengthwise with a floured fork. Bake at 400 °F for 8 to 10 minutes or until lightly browned. Cool 2 minutes before removing to a wire rack.