Global Const GW_OWNER = 4
Global Const SW_HIDE = 0

Declare Function GetWindow Lib "User" (ByVal hWnd As Integer, ByVal wCmd As Integer) As Integer
Declare Function ShowWindow Lib "User" (ByVal hWnd As Integer, ByVal nCmdShow As Integer) As
Integer

Sub SetFormInvisible (frm As Form)

  Dim ownerhWnd As Integer
  Dim dummy As Integer

  ' Make sure the form is invisible:
  frm.Visible = False
  ' Grab the background or owner window:
  ownerhWnd = GetWindow(frm.hWnd, GW_OWNER)
  ' Hide from task list:
  dummy = ShowWindow(ownerhWnd, SW_HIDE)
End Sub