Francisco de Asís Miralles Argente wrote:

I tried to backup only one file that is in a directory with other files in a windows client, but I don't get any way to do it.

The obvious DLE way does not work:

   your.host    /path/to/the/file    comp-user-tar

because dump and tar need a directory path; gnutar is given
the command "gnutar ... --directory /path/to/the/file ..."
so it needs a directory (or a symlink to a directory).

I never tried it, but recently you can also specify include
lists when using gnutar.  Maybe something like this works:

  your.host  file-bup /path/to/parent/dir {
       comp-user-tar
       include "./file"
       } 1



(Not tried myself, but curious if it works...)