Getting the View client's IP address

I have some code that uses the well established WTSQuerySessionInformation() API call (http://msdn.microsoft.com/en-us/library/aa383838(VS.85).aspx), via the WTSClientAddress argument, to retrieve the IP address of the client that is connected to an RDP session.

When this code is run inside a View session (on XP SP3), it always returns 127.0.0.1 rather than the IP address of the client connecting to the View session. If I disconnect the View session and reconnect as the same user via an RDP console session then the client IP address is correctly returned. Using the WTSClientName argument to return the client name always returns the correct client name, regardless of whether the session is connected through RDP or the View client.

Anyone got any ideas how I retrieve the client IP address please? Probably should be posted to a developer community but I can't really find a relevant one.