You didn't answer Peter's question. Is your application running in the context of a Web Browser or as a Desktop application? Since you posted your question in the ASP.NET forum, I am assuming you have a web app that you need to retrieve the full physical path of X folder and, as Peter said, you need to explain exactly what you are trying to do so that we can give you a more accurate answer.
Basically, you will use the FileSystemInfo Class of the System.IO namespace to achieve this but, again, alot of how you will ultimately accomplish this relies on exactly how you are trying to do this.
Read this if you want to know how to get a correct reply for your question:
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