选择任意文件夹作为浏览的开始文件夹(win32gui、win32com、shgetfolderlocation)

我想从一个文件夹开始,例如c:\test\ 而不是 任何 预定义的CSIDL_* 文件夹。 我怎样才能做到?

    ''' python 3.6.2 '''

    import os
    import win32gui
    from win32com.shell import shell, shellcon

    myfolder_pidl = shell.SHGetFolderLocation (0, shellcon.CSIDL_DESKTOP, 0, 0)

    pidl, display_name, image_list = shell.SHBrowseForFolder (
      win32gui.GetDesktopWindow (),
      myfolder_pidl,
      "Select a file or folder",
      0x00014050, #shellcon.BIF_BROWSEINCLUDEFILES and some more
      None,
      None
    )

    if (pidl, display_name, image_list) == (None, None, None):
      print ('Nothing selected')
    else:
      my_path = shell.SHGetPathFromIDList (pidl)

    file_to process = my_path.decode()

    ''' continue processing file_to_process
    '''