Sum of Random numbers must be greater than x and less than y

I would like for my code to express the sum of random numbers generated to be in a range. Between 120 and 235.
What's the best way to do that without changing my code too much?

I'm positive it needs to create 2 Dims and an if else statement, but I can't word it properly.
I'm using Visual Studio 2017

Public Class Form1

    Private Sub Button1_Click(ByVal sender As Object, e As EventArgs) Handles Button1.Click
        Randomize()

        TextBox1.Text = Rand(1, 100)
        TextBox2.Text = Rand(Long.Parse(TextBox1.Text), 100)
        TextBox3.Text = Rand(Long.Parse(TextBox2.Text), 100)
        TextBox4.Text = Rand(Long.Parse(TextBox3.Text), 100)
        TextBox5.Text = Rand(Long.Parse(TextBox4.Text), 100)
        TextBox6.Text = Rand(Long.Parse(TextBox5.Text), 100)
    End Sub

    Private Function Rand(v As Long) As String
        Throw New NotImplementedException()
    End Function

    Private Function Rand(ByVal Low As Long, ByVal High As Long) As Long
        Rand = Int((High - Low + 1) * Rnd()) + Low
    End Function
End Class