While I can't speak for the NA, take the CC course. I suspect that they'd look cross-eyed at an online course if it was not an accredited college and I doubt many of those would admit a HS soph. for a single course.
But of greater concern to me is your statement that you cannot "fit" a foreign language into your schedule. Most universities require at least 3 years of a language - and most make their acceptance decisions at the beginning of your senior year. So in your case you'll be filling out the application packets with only two years on your transcripts - while almost all of the other applicants will show 3. I see this as a major disadvantage (but I'm not an admissions officer so I may be totally off the mark.) Regardless, I would talk with your guidance office about making room in your schedule. Even if that means dropping some other class.