Public Sub saveAUrl(ByVal Str As String)
        Dim r As Regex
        Dim m As Match
        r = New Regex("(?<=<a.*?href\s*=\s*"")(?<1>[^""]*)(?=""|(?<1>\S+))", RegexOptions.IgnoreCase Or RegexOptions.Compiled)
        m = r.Match(Str)
        While m.Success
            MessageBox.Show(m.Value)
            m = m.NextMatch()
        End While
    End Sub

    saveAUrl(Me.RichTextBox1.Text)