you would need to use node to host your site, or at least part of it, instead of apache.
you could host node on a different port, and server your css files from that non-80 port.
the trouble with that is that relative paths in the css are broken. if you use full urls (starts with "http" in your css, it can work fine.
a refinement on that is to grab the non-80 port in php and re-serve it using php/apache from your site. with php using a simple 90-second APC-based cache to avoid repeated internal http requests each .less file view, the performance should be pretty solid.
let me know if you want more info on getting node to work alongside php.
I installed node and then I typed the line in the command window to activate less.js as it said on their website. If I create a rule in style.less and then link that to the index.html file along with the less.js it works.
However I need a normal style.css file to do all my other code in?