This would have to be done at the programs coding level. What you are talking about is turning a single core application into a dual core application right?
Say something like your browser. IF it needs the extra CPU to use the other core instead of taxing the 1 core.
This can only be done by the coders by making the applicationa a SMP (Symetrical Multiprocessing) applicaiton. Using 3rd party software wont help.