Per the guys at Pocket PC Addict, it appears the Tweaks2K2.NET tool will allow a pocket pc user to specify an alternate port using the built-in Terminal Services client. This has been a frequent request of the Pocket PC community and it is one I hope MS will include with the next rev of the Windows Mobile Software.
Remote Desktop: Pocket PC Tweak tool to allow access to alternate ports
Alert - Archived Data
Please note that the old Network Blog content (from http://www.networkblog.net) is included for historic purposes only. Much of this data is either no longer relevant or may be missing from the original source. Most of this data was back from my MVP age and is over ten years old. Thus, many of the links are no longer valid as Microsoft has changed the links on many of their Technet sites.