I come d' to buy zipcodesearch and I want to translate it into French. J' have make a part but l' other (surrounded in red ==> Find those listings nearest you) I do not know where is the file to modify.

You can find all of the template files here:

/components/com_mtree/templates/m2/

If this is the default search form, it is named:

page_ZCSadvSearch.tpl.php

You will normally find the default template on the configuration screen.

Thank you I have change the language.