No. When you pitch yeast, it will continue to multiply until the environment can't support it anymore. That's why you end up with a yeast cake at the end that is several times the volume of the original amount pitched. Pitching more will just give you a faster start - that is why many people use a yeast starter.
That being said, you can buy yeast that has a higher tolerance of alcohol, therefore continues to ferment to a higher alcohol content. Champaign yeast will yield a much higher alcohol content, but will also change the characteristics of the beer. But, there has to be the sugar there for it to ferment. Once all of the sugar is used up by the yeast, you're not getting any more alcohol, no matter how much or what kind of yeast you use.