There's a free program calleed VSTHost I've been getting into for this. It gives you total control over your VSTs, and you could use it to sample or do control via midi ala what Antonym was describing. It has the benefit of being able to control EVERY parameter of the VSTi, even ones which you cannot see through the GUI, plus a recording feautre, and all in a dedicated environment, so you don't need to load up a big CPU hogging DAW. Plus you can chain VSTi's and VST effects in any order you want, you could rout an output from your MPC into a chain of VST effects, and sample it back into your MPC. It would be great live if you wanted to use your PC and VSTi's as a sound module controlled off your MPC. Anyways, thats just some ideas i've had for using it, check it:
http://www.hermannseib.com/english/vsthost.htm