Not sure if it will overwinter in a pot, but a camellia would be evergreen and would do fine in part shade. You may have to protect the roots come winter, though. It would need to be trimmed to keep it small enough for the pot size you have.

There are tall narrow evergreens that will tolerate shade--fastigiate yews and cephalotaxus come to mind. Try Googling "cephalotaxus harringtonia fastigiata" and see if that pleases you. A good source for all plants is the Forest Farm nursery in Oregon. Welcome to gardening.