Quote - Help for dummy (me). With what program editor can I open flm file? Any tips thks

The film (flm) files are not actually supposed to be edited at all. What they're used for is to remember the exposed lighting information generated during a render done in Lux so that you can resume a given render in the future.

The only other use for it is to combine it with another one from a remote client via luxmerger.exe in the command line. Though, that's something Lux itself often calls if you are running the remote client and connect to it via the GUI or console version. More info at the LuxMerger wiki page or LuxBlend Output wiki page.