How to add string value to Windows registry?

I want to add this new registry entry via cmd/batch file to run CMD always as administrator. I know I can add it by navigating to the mentioned path in the command. But I want to add it in one of my batch files. And I think to add string value I need to modify my cmd. I am missing something here :-

reg.exe ADD \HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers /t REG_SZ "C:\\WINDOWS\\system32\\cmd.exe"="RUNASADMIN" /f

Can anyone help me with this please?

The command line to use in a batch file executed by 64-bit `cmd.exe` on Windows x64 or 32-bit `cmd.exe` executed on Windows x86 running under elevated environment of a local administrator is:

%SystemRoot%\System32\reg.exe ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers" /f /t REG_SZ /v "C:\WINDOWS\system32\cmd.exe" /d "RUNASADMIN"

Open a command prompt window and run `reg /?` and next `reg add /?` for help on used command __REG__ for adding a string value to Windows registry.