The Dynamic Data Center Toolkit for Hosters project have just put up the sample code for a Hyper-V ActiveX RDP control, available here:

What this allows you to do is to create a Remote Desktop connection directly to the virtual machine (not to the guest operating system) in exactly the same manner as when you are using the Virtual Machine Connection window in the Hyper-V Management Console.

As this is an ActiveX control you can even use it in a web page if you wish to.

Merci Ben, on imagine donc bien piloter des VMs Hyper-V depuis un XP avec cet ActiveX ;)