Android has to be built for the device - you can't just download a generic android onto any phone, even any Android phone. And where that device was not built for Android, doesn't have a suitable bootloader, then it takes time, knowledge and effort to crack the phone and port the OS to it. So unless you have those skills yourself, it's only possible if somebody who has them has done the necessary work.
Although some older HTC windows phones have had android ported to them (the HTC HD2 is the best known example), I can't find any sign that this has ever been done for the Radar. So unfortunately I doubt very much that it is possible.