求函數計算公式

請幫忙想求以下用函數計算公式:
請計算出...A部門所有人, 於1至3月份內, 總用開單有多少張?及合共佣金多少?


姓名..........部門.....開單日期.............俑金
CAT..........A..........2008/01/30..........$10
LULU........A..........2008/02/12..........$15
BOBBY.....B..........2008/04/18..........$13
PETER.......A..........2008/03/10..........$20
GEGE........A..........2008/06/12..........$4
APPLE.......C..........2008/07/13..........$6
MARY.......A..........2008/08/24..........$15
DODO.......A..........2008/03/15..........$32
MAY.........B..........2008/12/24..........$3