Dim instance As ExcelSheet
Dim col As Integer	'1から始まる列番号
Dim row As Integer	'1から始まる行番号
Dim format As String

instance.CellFormat(col, row, format)

'ExcelSheetクラス CellFormatメソッド

Public Class AddIn

    Private es As ExcelSheet

    Public Sub New()
        es = New ExcelSheet()
		es.SelectSheet(1)
		es.CellFormat(1, 1, "yyyy/mm/dd")	'A1
		es.CellValue(1, 1, "2012/7/8")		'A1
		es.CellFormat(1, 2, "yy/m/d")		'A2
		es.CellValue(1, 2, "2012/7/8")		'A2
		es.Save("D:\tmp\sample2.xlsx")
		es.Dispose()
    End Sub

End Class