Aside from getting a utility that supports your CPU to overclock with, there's nothing you can do. Sin's is a single core/threaded game and because of this is extremely CPU limited. (as long as you meet the basics for Ram/GPU of course)

Anyways get your CPU's model and look online for tweaking utilities that support it / the laptops mobo, you might have luck or may not, that's even if you can get one, then the trouble is OCing something that is so small and prone to heat issues hehe.