Spazio tra lettere e numeri

Private Sub Carica_Dati()
        strSQL = "SELECT * FROM " & Database & "." & Tabella & ""
        Dim data_Adapter As MySqlDataAdapter

        ' Create the SqlDataAdapter.
        data_Adapter = New MySqlDataAdapter(strSQL, Connection)

        ' Map Table to Contacts.
        data_Adapter.TableMappings.Add("Table", Tabella)
        ' Fill the DataSet.
        m_DataSet = New DataSet()
        data_Adapter.Fill(m_DataSet)
        ' Bind the DataGrid control to the Contacts DataTable.
        'DataGrid1.SetDataBinding(m_DataSet, "authors")
        DataGridView1.DataSource = m_DataSet
        DataGridView1.DataMember = Tabella
    End Sub

        Dim TestoTarga As String = TextBox1.Text
        Dim TargaFormattato As String
        Dim actcar As String
        Dim lastcar As String

        For i = 0 To Len(TestoTarga) - 1

            Dim Carattere As String = Microsoft.VisualBasic.Mid(TestoTarga, i, 1)

            Select Case Carattere
                Case "1", "2", "3", "4", "5", "6", "7", "8", "9", "0"
                    actcar = "numero"
                Case Else
                    actcar = "lettera"
            End Select

            If lastcar = "lettera" And actcar = "numero" Then TargaFormattato &= " "
            If lastcar = "numero" And actcar = "lettera" Then TargaFormattato &= " "

            TargaFormattato &= Carattere

            lastcar = actcar

        Next