  Public Function MyAdd(ByVal a As Double, ByVal b As Double, ByRef retM As Integer) As Double(,)
        Dim ret(0, 0) As Double
        ret(0, 0) = a + b
        retM = 1
        Return ret
    End Function
    Public Function MyAdd(ByVal a(,) As Double, ByVal a_M As Integer, ByVal b As Double, ByRef retM As Integer) As Double(,)
        Dim i, j, n As Integer
        retM = a_M
        n = a.Length \ a_M - 1
        a_M -= 1
        For i = 0 To a_M
            For j = 0 To n
                a(i, j) += b
            Next
        Next
        Return a
    End Function