Dotclear import using the flat text file

Request for import procedure from Dotclear to WordPress:

There is a new plugin for Dotclear 1.2.5 here
https://www.dotclear.net/plugins/plugin-flatExport-1.1.tar.gz
to backup the dotclear blog in an utf8 flat text file.

I try to modify the livejournal.php to import such a file, without success. If somebody with wordpress knowledge can do that, welcome and thanks in advance.