You want to deploy mapped drives only to users who have French configured as their local language[rl1] . What feature of Group Policy preferences allows you to do this?
Quick check answer
You can use item-level targeting with Language targeting selected.
The above tip was excerpted from Mitch Tulloch's book Training Guide: Installing and Configuring Windows Server 2012 from Microsoft Press.
Mitch is a nine-time recipient of the Microsoft Most Valuable Professional (MVP) award and a widely recognized expert on Windows administration, deployment and virtualization. For more information see http://www.mtit.com