@topic: I'm going to use this chance to plug this tutorial I've written.
Dimensio: haven't tested myself, but this link and some below that could give a decent answer to your post.
That's already the method that I'm using. USB Loader GX looks in sd:/apps/gc_devo for Devolution, and HBC will load it from there also. Loading GC games from the loader works on my Wii console, but not on my Wii U. If I run Devolution directly from HBC on the Wii U, however, I can launch anything on sd:/games that I have already authenticated to my Wii remote on my original Wii console.
It's the same SD card and the same USB storage, swapped between systems, so I know that isn't the problem. Initiating Devolution from USB Loader GX seems to kill the connection to the Wii remote, unless I'm doing something wrong.