Convert a mapped drive to a full UNC path

Universal/Uniform Naming Convention. A UNC path describes the location of a volume, directory, or file.

The format for a UNC path is \servervolumedirectoryfile and is not case-sensitive. For example:

\Shared1_svr\Shared1\WGroups\NetworkOrders.xls

Rather than describe the location of a file or directory by drive letter, the Network Group will typically communicate a UNC path to describe the actual location of a file or directory. Windows drive letter mappings are arbitrary, whereas a UNC path is specific and applies to all operating systems.

Note: The UNC method started with the UNIX operating system. UNIX uses the forward-slash character as a path separator. Many network services (ex. FTP) have their origins in the UNIX operating system, so they use forward-slashes instead of the backslashes that DOS/Windows uses. It is important to recognize this distinction when using these services.

Usage:

UNCLabel.Caption := ConvertToUNCPath(ExtractFileDrive(Edit1.Text)) ;

Followings are the source can get UNC Path.
 

function ConvertToUNCPath(MappedDrive: string) : string;
var
   RemoteString : array[0..255] of char;
   lpRemote : PChar;
   StringLen : Integer;
begin
  lpRemote := @RemoteString;
  StringLen := 255;
   If WNetGetConnection(Pchar(ExtractFileDrive(MappedDrive)) ,
                        lpRemote,
                        StringLen) = NO_ERROR Then
     Result := RemoteString
   Else
     Result:=''; // Alternatively return an errorcode, Raise an exception or something like end;
end;