Ask HN: How can I form a startup when I can't be CEO?

I have an idea for a startup. Right now it's just a hobby- I've been piecing together code for it in my spare time. But I've reached a point where I need the help of someone with a different skillset than mine (augmented reality, 3D projections, that sort of thing). Effectively, I need a co-founder, and that's going to mean getting a little more serious about my hobby project.

But I have a problem: I'm in the US on an H1B visa. I can't be the CEO of a company, and I can only work at one job (my current one). Has anyone on HN dealt with a scenario like this that can give me some hints as to whether this would ever work out?

It seems like my best case scenario would be to take the work as far as I possibly can (in actually making the app and web site) before formally setting up a company- at which point I would have to withdraw entirely from the day-to-day of the company, hold shares and sit on the board (which, AFAIK, I am able to do). Could a lawyer draw up some paperwork between myself and the US citizen co-founder outlining the roles I would take once I was legally able?

I could, of course, just go home and set up my company there. But then I'd be very much out of the tech scene (although London has one, it's not great) I'd be losing my potential investors, as well as a very nice life in NYC. If at all possible I want to do this in the US, I just don't know how realistic I am being. Any hints?