[cionci]

Declare Function CreateFile Lib "kernel32" Alias "CreateFileA"
            (ByVal lpFileName As String,
             ByVal dwDesiredAccess As Long,
             ByVal dwShareMode As Long,
             ByVal lpSecurityAttributes As Long,
             ByVal dwCreationDisposition As Long,
             ByVal dwFlagsAndAttributes As Long,
             ByVal hTemplateFile As Long) As Long

Declare Function WriteFile Lib "kernel32"
            (ByVal hFile As Long,
             lpBuffer As Any,
             ByVal nNumberOfBytesToWrite As Long,
             lpNumberOfBytesWritten As Long,
             lpOverlapped As OVERLAPPED) As Long

Declare Function ReadFile Lib "kernel32"
            (ByVal hFile As Long,
             lpBuffer As Any,
             ByVal nNumberOfBytesToRead As Long,
             lpNumberOfBytesRead As Long,
             lpOverlapped As OVERLAPPED) As Long

Declare Function CloseHandle Lib "kernel32"
            (ByVal hObject As Long) As Long

Public Const GENERIC_READ = &H80000000
Public Const GENERIC_WRITE = &H40000000
Public Const OPEN_EXISTING = 3
Public Const FILE_FLAG_OVERLAPPED = &H40000000

'********************
Type OVERLAPPED
  Internal As Long
  InternalHigh As Long
  offset As Long
  OffsetHigh As Long
  hEvent As Long
End Type

All'inerno dell'onclick del bottone ci emtti questa roba :

Dim hFile As Long
Dim ret As Long
Dim number As Long
number = 0

hFile=CreateFile("LPT1", GENERIC_READ Or GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0)

If hFile <> INVALID_HANDLE_VALUE Then
   ret = WriteFile(hFile, "Ciao", 4, number, 0) 
   CloseHandle(hFile)
End If

Comunque non lo posso provare...