[JohnM]

REW measures the room's impulse response, that is how it produces the frequency response plots. You can export the impulse response REW measures for use with convolver and similar packages. You can also export the impulse responses of filter setups, which is probably more useful in this instance - i.e. you would use REW to make your measurements and set up the filters to correct the response, then export the impulse response of the filters to apply it with convolver (for example).