When you use SetWindowPos in this respect, you don't need to declare all the constants, because you only need to '3' as the flag. This can shorten your by a lot.
Code:
Private Declare Function SetWindowPos Lib "user32" (ByVal hWnd As Long, ByVal hWndInsertAfter As Long, ByVal X As Long, ByVal Y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long

Private Sub Command1_Click()
    SetWindowPos hWnd, -1, 0, 0, 0, 0, 3
End Sub