how to execute node js function from javascript

I am creating a java web application and i would need to access the machine's environment variables that opens my site, in this case i would use username and domain. These data help me to exploit single sign on technology. I found that with js node obtaining such data is really easy, in fact two lines of code are enough:

console.log (process.env.USERNAME);
console.log (process.env.USERDNSDOMAIN);

Assuming you can install on each intranet node js machine, the question now is this: how can i run node js code from the usual javascript code that is contented on a web page?

Thank you all (and sorry for my english)

via Marco R.