I have a question, let's say you've written two or three books, and you decide you want to turn those books into films, and you have already taken SEVERAL Hands-on workshops on filmmaking and have actually made a few films yourself with your own video camera, and you want to be the director of the films or scripts that you are writing. Can you demand or, tell or ask an agent or studio, I'll sell you my script if I can be the director of the film? Especially if you have TONS of hands-on filmamking experince and have made some films of your own?
I hate to say it, but you sound like a film rights agent's worst nightmare. In terms of novels to film, there are two main scenarios: 1) routine pickup of a film rights option when a novel publishes. Typically this might be a matter of a few thousand dollars that the studio will lay out "just in case." It may be for a limited period, like a year, and you get a bunch more money if they ever decide to make a film; 2) on the other hand, if you've held off on selling rights and you're lucky enough to have a blockbuster novel, you are probably looking at six or even seven figures in film rights, maybe even a percentage of revenue. Rest assured the studio will be paying very close attention to the issue of who and how when laying out that level of money. Generally in the last case, they don't want your screenplay; they will hand it off to someone in their stable. They might pay you the lip service of looking at it, but that's about it.
If you're talking about unpublished novels that you've turned into screenplays, then nobody cares if they started as novels or not. Why should they? It's all about the screenplay. So you're on a level with a gazillion other screenwriters trying to ply their trade, and most of them aren't asking to direct their own films. Even if you've published a blockbuster, about the best you might be able to do is push to get a certain director or actor you admire, particularly if your agent can get him/her to read your script. Otherwise, you are pretty much at their mercy unless you're willing to kiss a lot of money goodbye.
Remember, even as successful an author as Thomas Harris (creator of Hannibal Lecter) got manhandled by Dino DiLaurentis, who threatened to do a Hannibal-type movie not based on one of Harris' books because of an obscure clause in Harris' contract. Harris ended up writing a book he didn't want to,
Hannibal Rising, just to control the content of the movie.
But far more important, you could very well overestimate your own abilities in something like this. You probably have little or no experience with anything remotely big-budget. You probably haven't got a clue how to manage the colossal egos of actors, cinematographers, sound guys, special effects wizards, film music composers and the like. You have no idea how to deal with the conflicting wants of actors, producers, accountants, and so on. There are probably fifty pieces of equipment on a Warner Brothers sound stage that you would barely even recognize. The minute a studio starts listening to your answers to questions about how you'd approach turning your novel into film, you'd probably see about fifty raised eyebrows and a hearty "We'll get back to you."