Programming Editor on Terminal Services

We run Linux Thin Clients (Old PCs) on Windows 2003 Server Terminal services. Is there any way we can make the Software work using the Thin Clents serial port ?. Apparently 2003 TS will forward serial ports using a command 'net use com5: \\tsclient\com1:' which forwards com5 to the thin client. It can't be used for the servers own hardware ports, and the Editer software will only use the servers hardware ports. So is there a solution or do we have to go back to using PCs ?. Some of the hardware we're using for thin clients isn't up to running a modern operating system like XP which some other software we use requires.