It's going to be far from "not that helpful" in that laptop, I'm afraid.
Laptops' cooling solutions are usually barely sufficient for stock operation, overclocking will push you into thermal throttling territory, if not full thermal shutdown.
On top of that, the power solution is similarly only sufficient for stock operations +a few%. Any OCing that requires boosting the power draw/voltage, could push you beyond the scope of it's capabilities.
A c2d T5900 + GS9300M, even overclocked, aren't going to be capable of much by modern standards.
Best to focus on titles it *could* handle at launch.
MSI Afterburner might let you OC the GPU, although I wouldn't be surprised at all if OCing &/or power limit is locked at a GPU BIOS level.
Then, you could consider flashing somewhat custom BIOS' to the GPU..... but if you can't afford a new laptop/PC anytime soon, that's not likely worth the risk.
Similarly, there may be custom BIOS' in existence to allow some OCing of the CPU (likely BCLK only).... but they'd be custom, unverified, and run the risk of bricking your laptop.
There are utilities out there that allow you to OC mobile CPUs. I don't see them serving any purpose whatsoever, so won't be linking any here..... but Google would be your friend there.
I'd highly suggest you DO NOT go this route but, if you do, good luck!