Its a brainfuck interpreter in batch! :D
You can learn more about brainfuck here.
Brainfuck has been proven to be turing complete (In fact, it was created to be turing complete and to run on the smallest interpreter), meaning batch is turing complete too!
Executing is easy:
$ interpreter < examples/hello.bf > CON
Alternatively, you can input your own program into stdin followed by a empty
line and a CTRL + Z keypress to input a EOF character and start the program:
$ interpreter
,.,.,.,.,.,.!Hello!
^Z
The input file must have CRLF line endings or the program will loop forever.
It is also recommended to minify the code before passing it to the interpreter, as some characters like the quotation mark might prove to be problematic.