I find those instructions hard to understand, particularly to someone without experience with C.
I have once posted one example here: Calling a Fortran routine from a library which uses LAPACK - #5 by lmiq (but I arrived to succeed in those by finding several examples around, not reading the docs).
To do the same with that code, you need first to convert the program into a subroutine, but the way that is structured doesn’t help.
Probably the first thing to ask is how fast you need that to be. Maybe parsing the output is good enough.