Orange juice and orange concentrate are not good ideas. Zest could work out well. But basically most citrus fruits, especially oranges, get a really stale and unpleasant taste when fermented (hence why "orange wine" doesn't exist). Orange zest, on the other hand, can give a very fresh and pleasant orange flavor. I've personally never tried this with cider as I personally don't think apples and oranges mix that well, but if you do try it, I think zest would be the best approach.