Using the Dir method :
Sub Dir_Use()
Dim i As Long
Dim FileList()
Dim FSO As Object
Dim oFile As Object
Dim strPath As String
strPath = "c:\test"
Set FSO = CreateObject("Scripting.FileSystemObject")
FileList = Read_FilesNames_From_Folder(strPath)
Set oFile = FSO.CreateTextFile(strPath)
For i = LBound(FileList) To UBound(FileList)
    oFile.WriteLine FileList(i)
Next i
oFile.Save
oFile.Close
Set FSO = Nothing
Set oFile = Nothing
End Sub
Function Read_FilesNames_From_Folder(InitilFolderPath As String) As Variant
With Application
    .EnableEvents = False
    .DisplayAlerts = False
    .ScreenUpdating = False
    .Calculation = xlCalculationManual
End With
Dim FileName As String, _
    FolderPath As String, _
    Results()
ReDim Results(0)
With Application.FileDialog(msoFileDialogFolderPicker)
    .InitialFileName = InitilFolderPath
    If .Show = True Then
        FolderPath = .SelectedItems(1)
    Else
        Exit Function
    End If
End With
FileName = Dir(FolderPath & "*.xlsx")
Do While FileName <> ""
    Results(UBound(Results)) = FileName
    ReDim Preserve Results(UBound(Results) + 1)
    FileName = Dir
Loop
ReDim Preserve Results(UBound(Results) - 1)
With Application
    .EnableEvents = True
    .DisplayAlerts = True
    .ScreenUpdating = True
    .Calculation = xlCalculationAutomatic
End With
Read_FilesNames_From_Folder = Results
End Function
Or with your initial code, something like this to select folder via FileDialogFolderPicker :
Sub test_Marcos_Busto()
Dim Dir1 As String
With Application.FileDialog(msoFileDialogFolderPicker)
    .InitialFileName = "c:\test"
    If .Show = True Then
        Dir1 = .SelectedItems(1)
    Else
        Exit Sub
    End If
End With
'You don't use Dir1 afterwards... So, I'm not sure where to go afterwards
Order1 = "type *.b*>>mat.txt"
Order2 = "dir/b>lista.txt"
Call Shell("cmd.exe /S /K" & Order1, vbNormalFocus)
Call Shell("cmd.exe /S /K" & Order2, vbNormalFocus)
End Sub