Delphi: get the session number

we have an application that runs on w2003 server and is used via RDP by N remote users. When accessing the application, users share their local virtual printer PDFCreator. When a user accesses the server, we need a way to store the number of his session with a call to some windows API. The number should be the one that is used by windows when listing the avaialable printers (see attachment). The coder will suggest the few lines of Delphi code needed to get the session number so that the printer of the current user is quickly identified in the printer list. ## Deliverables we expect you to provide 2-3 lines of code at most