I have cretaed new addon for reporting with in that just created report folder and .py files to call default account template .rml file(RML path is addons/account/account_print_invoice.rml). After that installed the addon and generated the po files for Dutch language from Setting > Translation> Import/Export > Export Translation. I didn't find any contents for translation in that po file. My .po file look like this:

# Translation of OpenERP Server.
# This file contains the translation of the following modules:
#
msgid ""
msgstr ""
"Project-Id-Version: OpenERP Server 7.0\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2014-05-27 06:11+0000\n"
"PO-Revision-Date: 2014-05-27 06:11+0000\n"
"Last-Translator: <>\n"
"Language-Team: \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: \n"
"Plural-Forms: \n"

Please help me to generate language file.