Transferring Steam files to Origin?

Hey, so I bought Dragon Age: Origins Ultimate Edition as part of the Humble Bundle a few months back, so they're the same version between Steam and Origin, but I can't seem to get Origin to pick up the files I've already downloaded... I'd rather not have to download 8GB again since I'm Australian and my internet sucks. I've changed the install directory, restarted Origin and still nothing, it keeps trying to download the whole thing. Any help?