How to retrieve the path to a client machine Special Folders running RemoteApp as a filepath string?

Question

// Set default workspace directory
string initialDirectoryString = @"C:\work\";
// Check if remote session, and get the local drive location
if(System.Windows.Forms.SystemInformation.TerminalServerSession) {
    initialDirectoryString = @"\\tsclient\C\work\";
}

Originally when I wrote the above code, I was under the impression that we could create a directory in C:\ to write to, but from what I've been told, the only location they have acces to is the My Documents directory.

So, I know I can retrieve the local Environment.SpecialFolder with:

string path = System.Environment.GetFolderPath(Environment.SpecialFolder.Personal);

The problem is how to retrieve from the client machine. I thought about retrieving the path from the server and prepending \\tsclient\ (and removing the : from C: etc.), but then if the My Documents directory isn't the same on the client as (V: instead of D:, for example), then I would get an Access Denied when I try to write to the location.

Is there a way to that I can specify a string similar to CMD where you can use %USERPROFILE%/My Documents, but with tsclient?

Edit: I found that I can use Environment.ExpandEnvironmentalVariables() to change the %USERPROFILE%\My Documents to an absolute path.

string MyDocumentsLocation = Environment.ExpandEnvironmentVariables(@"%USERPROFILE%\My Documents");