跪求一个vb程序 计算π值 精确到小数点后100位

Private Sub Command1_Click() Dim a As Long, b As Long, d As Long, e As Integer, f(801) As Long, g As Long Dim i As Long Dim res As String Dim index As Long a = 10000 c = 800 For i = 0 To c f(i) = a / 5