PowerShell can't create folder on network mount

I've create a drive with the Letter Z: and shared it so that the Network Path is: \GOELA2682012SRVsrv2012r2

I now want to create a folder on there using PowerShell.

This doesn't work: New-Item -Path "\GOELA2682012SRVsrv2012r2Userstest" -ItemType Directory

While this does work: New-Item -Path "Z:Userstest" -ItemType Directory

Why?