Did you tried Lync 2013 Translation yet J
Ok, copy the below lines to a text file on your machine, save as *.reg, then merge it to your windows registery.
Now restart your Lync 2013 and start a conversation,
Configure the language,
Now start your conversation.
Did you noticed the small icon beside the incoming conversation translation? It’s good.
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Windows Registry Editor Version 5.00
[HKEY_CURRENT_USERSoftwareMicrosoftOffice15.0LyncAddins{2b26edf9-92e0-4d9c-9d7a-f772fcd4f31b}]
"Name"="Lync Conversation Translator"
"Parameters"=""
"ExtensibilityApplicationType"=dword:00000000
"ExtensibilityWindowSize"=dword:00000001
"DefaultContextPackage"=dword:00000000
"InternalURL"="http://go.microsoft.com/fwlink/?LinkID=68810&Lync=y"
"ExternalURL"="http://go.microsoft.com/fwlink/?LinkID=68810&Lync=y"
[HKEY_CURRENT_USERSoftwareMicrosoftOfficeLyncSecurity]
[HKEY_CURRENT_USERSoftwareMicrosoftOfficeLyncSecurityTrusted Sites]
[HKEY_CURRENT_USERSoftwareMicrosoftOfficeLyncSecurityTrusted Sitesconversationtranslator.cloudapp.net]
"http"=dword:00000001
"https"=dword:00000001
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Near to 10 years in the IT service delivery, and since 2013, I have managed 25 experts and with them, we delivered 700 successful projects, through 10k Man days of service, added to $100M hardware to draw a 700 beautiful IT infrastructure architecture. Experience and result-oriented approach, side by side with professionalism and team-work achieved a strong track record in developing and implementing successful strategic business plans, demonstrating a strong technical, leadership, business, communication, presentation and analytical competencies.
Hany Taha 
Your *.REG file is broken, you’re missing some slashes:
[HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Lync\Addins\{2b26edf9-92e0-4d9c-9d7a-f772fcd4f31b}]
as well as in all the other keys.
Thanks for clarification, will check and update.