sub HDI_FORMAT {0x4} sub HDF_SORTDOWN {0x400} sub HDF_STRING {0x4000} sub HDM_SETITEM {0x1200 + 4} $hditem = pack("LLLLLLLLLLL", HDI_FORMAT, # mask 0, # cxy 0, # pszText 0, # hbm 0, # cchTextMax HDF_SORTDOWN | HDF_STRING, # fmt 0, # lParam 0, # iImage 0, # iOrder 0, # type 0 # pvFilter ); $hditem_ptr = pack('P44', $hditem); $hwnd = $myListView->GetHeader();