I'm not sure what you're getting at, but msgplus doesn't build itself into Windows Live Messenger at all, it simply "hooks" itself when Windows Live Messenger starts up using a special .dll that is stored in C
Program Files\Messenger Plus! Live. There are many reasons that Messenger Plus! Live will not work with Windows Live Messenger Lite, they've probably just got conflicting code or features, the best bet would be to get into contact with the creators of WLM Lite.