Hi,
The javascript will execute on the machine that is running the web browser, whereas I think any C code that you write you will wish to run on the web server,
right? If so, then your problem can be broken down to a need to transfer the result of the javascript execution to the server, via the network connection.
The conventional way to do this is to use (say) PHP running on the web server, and therefore PHP could execute a C program (and pass a parameter to your
C program), or alternatively use PHP to write to a file, which your C program can parse.