（１）sumif・sumifs関数

科目集計・月別集計は
エクセルでは
=SUMIF($B$3:$B$15,E3,$C$3:$C$15)
=SUMIFS($C$3:$C$15,$A$3:$A$15,">=2013/4/1",$A$3:$A$15,"<=2013/4/30")
VBAの科目集計・月別集計は
Sub keisan()
    Dim i As Long
    Dim kotae1 As Long
    Dim kotae2 As Long
    Dim kotae3 As Long
'科目集計
    For i = 3 To 15
        Select Case Cells(i, 2)
            Case "商品"
                kotae1 = kotae1 + Cells(i, 3)
            Case "交通費"
                kotae2 = kotae2 + Cells(i, 3)
            Case "事務用品"
                kotae3 = kotae3 + Cells(i, 3)
        End Select
    Next
    Cells(3, 6) = kotae1
    Cells(4, 6) = kotae2
    Cells(5, 6) = kotae3
'月別集計
    kotae1 = 0
    kotae2 = 0
    kotae3 = 0
    For i = 3 To 15
        Select Case Cells(i, 1)
            Case "2013/04/01" To "2013/04/30"
                kotae1 = kotae1 + Cells(i, 3)
            Case "2013/05/01" To "2013/05/31"
                kotae2 = kotae2 + Cells(i, 3)
            Case "2013/06/01" To "2013/06/30"
                kotae3 = kotae3 + Cells(i, 3)
        End Select
    Next
    Cells(3, 8) = kotae1
    Cells(4, 8) = kotae2
    Cells(5, 8) = kotae3
End Sub