So, you downloaded Numlang's source for this.. Well done.
Now, here's the syntax.
1 = Exit and print the output
2 = Add 1 to value
3 = Subtract 1 from value
4 = Loop x times and add 1 to value each time (x being the next number, cancels out all effects, like the 1 exit)
5 = Print "Hello, world!"
6 = Value Squared
To make a simple hello world, it's just the string "51". The end! See the next part which im making soon
also it really likes to throw an error if the value is greater than 62