I think (but I am not sure) that if you only install the spell checker from an office product the spell checker from OE will work.
The spell checker in OE is a shared feature with Office aplications. I would try it out, getting a copy of office from a friend and chosing custom install, then install only spellchecker and dictionaries that you find. This is just a suggestion and I have no idea if it will work.
Good Luck