You cannot use this module to access a mapped drive in another Ansible task, drives mapped with this module are only accessible when logging in interactively with the user through the console or RDP.
Ultimately due to the security model of Windows this is not possible and as you can see the Z: drive has been mapped to the path you specified when you logged on locally. We’ve documented some of these limitations here https://groups.google.com/forum/#!topic/ansible-project/5uk0-ki7zT8 but ultimately you have a few options;