IIRC (Away from books ATM) the process for enchanting says "First proceed as if you were inventing the spell for level calculations" or something to that effect. If so, I'd say it's basically inventing the spell as an enchantment rather than as a pure spell.
Original research is also something that takes a very long time -- 10 years of full-time lab work is something to be expected -- so it is unlikely that you will want to go there with players just discovering Ars Magica.