Well, if you went to Concordia, you'd already be in a film-based program (granted, not the specific program you were hoping for). If you went to York, you'd be at the school you want to be at, but you would not be in a film-based program. So, there are pros and cons in both situations I suppose.
In
this discussion , there is a guy who posts at the bottom about a similar situation (his name is mdc3000, he posted last). He didn't make it into the film program, but did a common fine arts year, and then transfered over the following year. BUT, he stated that he knows others who have tried this, and have been unsuccessful. Now, you were saying that you would take some film-related courses, which would show the commitee that you're enthusiastic about film. Also, York has a very large Fine Arts community, and from what I have heard, there is a good collaboration between the various art departments - so I'm sure you could get involved with some student productions (specifically if they are outside the program criteria). You might be able to rent out film/video equipment too (I'm not too sure about this though).
If I was in your shoes, I'd probably be doindg the same thing you are doing - asking questions and trying to choose the best option. For starters, I would try and contact mdc3000 from that link I posted, and maybe he could offer some advice. From what I can tell, it seems like you really want to be at York, but I wouldn't rule out the Film Studies program at Concordia. The good thing about first year at film schools is that there isn't a HUGE difference between programs (or, so I've heard). I Imagine that most of the more hands on film stuff comes in the subsequent years. So, to be honest with you, if it were me I would choose Concordia, and then try and transer to York for my second year.
In the end though, I guess its all up to you, what you're looking to gain from first year, and ultimately where you want to end up. The good thing about your situation is - no matter where you go (York or Concordia), you'll be getting a good education, and be in a good film environment.