I don't think it is possible to mod a stock Intel cooler with screws, but if you want to OC I would go for another cooler anyway.
There are lots of good coolers around for very interesting prices. I don't know what the price for a Xigmatek HDT-S1283 or a OCZ Vendetta 2 is in your country, but if you look at the benchmarks of these coolers and their prices, I would certainly go for a cooler like that.
However, here a principle I explained in my first post comes into reality. These coolers both have push pins as standard mounting system, but like most branches Xigmatek sells an additional bracket with screws for the HDT-S1283 but it also fits on the OCZ vendetta 2. So if you would buy one of these coolers, do not forget to get that bracket for optimal contact between the HSF and the CPU.