vba中11/13如何让它显示到小数点后30位呢

看别人写过，我也写一个，竖式的算法。
Sub te()
Dim a As String
b = 11
c = 13
If b / c <= 999999999999999# Then
aa = b \ c
Else
Exit Sub
End If
b = b - aa * c
a = aa & "."
For i = 1 To 30
aa = (b * 10) \ c
a = a & aa
b = b * 10 - aa * c
Next
MsgBox a
[A1] = "'" & a
End Sub