> May be obvious, but I can't found it.
>
> I need to export some data to external, to be imported by another
> aplication...
>
> I create a external file (sucesfully) and export the data... ok.
>
> But I can't use DELETE FROM to empty the table for next use.
>
> Where is the way?

External tables support only SELECT and INSERT operations,
no UPDATE, no DELETE.
You can delete/modify the file - either after all users disconnect,
or when you drop external table definition.

Ivan
http://www.volny.cz/iprenosil/interbase/