I have an application which I've developed for a friend. It sends a POST request to the VB forum software and logs someone in (with out setting cookies or anything).

Once the user is logged in I create a variable that creates a path on their local machine.

c:\tempfolder\date\username

The problem is that some usernames are throwing "Illegal chars" exception. For example if my username was mas|fenix it would throw an exception..

Path.Combine( _      
  Environment.GetFolderPath(System.Environment.SpecialFolder.CommonApplicationData), _
  DateTime.Now.ToString("ddMMyyhhmm") + "-" + form1.username)

I don't want to remove it from the string, but a folder with their username is created through FTP on a server. And this leads to my second question. If I am creating a folder on the server can I leave the "illegal chars" in? I only ask this because the server is Linux based, and I am not sure if Linux accepts it or not..

EDIT: It seems that URL encode is NOT what I want.. Here's what I want to do:

old username = mas|fenix
new username = mas%xxfenix

Where %xx is the ASCII value or any other value that would easily identify the character.