How to get the absolute path of a css/js file by an area, theme and module?

I have a requirement to change css file dynamically for that I need absolute physical path of css in frontend and adminhtml area.
I want css file path based on area, theme and module in pub/static folder.
Thanks for your time.

I think you just use a wrong way of solving the task.

Your suggested way seems better, Thank you very much for quick reply.