this suggests a permission issue accessing \\servername\share\
i would try setting deployment to elevated token
https://batchpatch.com/remote-execution-context
alternatively, you could place the batch file and msi in the same directory, select ‘Copy entire directory contents in addtion to the specified file’, and change the executable path to
msiexec /i “%~dp0NSCP-0.5.2.35-x64.msi” /norestart