OK. You can compile the spl2c using MinGW if you don't want to try cygwin.
I set my students writing an SPL(*) compiler as an exercise, to help them I made a your tube video of downloading and using the MinGW software. Its simple enough for most dummies.
https://www.youtube.com/watch?v=58I6nAybzzI&list=PL3czsVugafjNLmIHA8ODBxuwWy8W4Uk9h&index=2
(*) Actually its a different SPL