There are lots of example code on the net. Izaz has given one such link. You need to connect a Integrated IR receiver ( Like TSOP1738) to a interupt pin.
If you just want to make the project and do not want to get into nitty gritty of the actual code. you can use bascom51 from bipom. it has a getrc5 command which makes life a lot easier for IR reception, you can get the address and command and use them accordingly.

Or if you want the assembly code mail me at
vinodkp@sancharnet.in