I would say it is a bit of a long shot saying Lelouch got his code from CC in the first episode. I'm pretty sure a user's Geass has to progress to a certain point before being able to be given the code. the Geass has to at least become permeant I would say. Look at CC's flashback on how she received her code. The Nun waited until CC's Geass was strong enough.
It's possible to say he got it later on from CC. The first chance I would say Lelouch could have received a code is when lelouch got both eyes to turn into geass's in his fight with Charles.