C:\Users\Lotus1>perl -v
This is perl 5, version 22, subversion 1 (v5.22.1) built for MSWin32-x64-multi-thread
[...]

C:\Users\Lotus1>perl -e" print system 'test1.bat' " 

C:\Users\Lotus1>exit 1 
256
C:\Users\Lotus1>perl -e" print system 'test1b.bat' " 

C:\Users\Lotus1>exit /b 1 
256