the rawmouse api looks promising.
however, to use the api one has to know a hwndTarget - that’s an int identifier for a specific window. and only if that window is active the lib is doing what it’s supposed to do.
since i seem to have no access to the window handle of neither the plugin host nor any other handle kinda fail on this task.
edit: http://www.codeproject.com/KB/system/rawinput.aspx is showing a very similar way to do it with multiple keyboards. by setting some flags they capture all input and identify the keyboard it came from, regardless of the active window.
however, even then a windows handler is needed.