Private Declare Function GetEnvironmentVariable Lib "kernel32.dll" Alias _
  "GetEnvironmentVariableA" (ByVal lpName As String, ByVal lpBuffer As String, _
  ByVal nSize As Long) As Long
Private Declare Function SetEnvironmentVariable Lib "kernel32.dll" Alias _
"SetEnvironmentVariableA" (ByVal lpName As String, ByVal lpValue As String) As _
Long
 
Private Sub Form_Load()
  Dim Buffer As String
  Dim l As Long
 
  l = 256
  Buffer = String$(l, Chr$(0))
 
  'auslesen
  l = GetEnvironmentVariable("test", Buffer, l)
 
  If l <> 0 Then
    Buffer = left(Buffer, l)
  Else
    'setzen
    Call SetEnvironmentVariable("test", App.Path & "/" & App.EXEName & ".exe")
  End If
End Sub