Function SearchListViewItems(ByVal text As String, Optional ByVal CaseUnsensitive As Boolean = False, Optional ByVal colIndex As Integer = 0, Optional ByVal atStart As Boolean = False) As ListViewItem()
        Dim options As System.Text.RegularExpressions.RegexOptions = IIf(CaseUnsensitive, System.Text.RegularExpressions.RegexOptions.IgnoreCase, System.Text.RegularExpressions.RegexOptions.None)

        Dim items As New List(Of ListViewItem)
        For Each li As ListViewItem In ListView1.Items
            If atStart AndAlso System.Text.RegularExpressions.Regex.IsMatch(li.SubItems(colIndex).Text, "^(" & text & ").*", options) Then
                items.Add(li)

            ElseIf Not atStart AndAlso System.Text.RegularExpressions.Regex.IsMatch(li.SubItems(colIndex).Text, "(" & text & ")", options) Then
                items.Add(li)
            End If
        Next

        Return items.ToArray
    End Function

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        PopolaListView()

        Dim items As ListViewItem()

        'cerco nella seconda colonna i numeri di telefono che iniziano con 02
        items = SearchListViewItems("02", CaseUnsensitive:=True, atStart:=True, colIndex:=1)


        'se ne ho qualcuno, pulisco e aggiorno la listview
        If items IsNot Nothing Then
            ListView1.Items.Clear()
            ListView1.Items.AddRange(items.ToArray)
        End If

    End Sub