[LAU] jack in -> alsa out

Hi, Does anyone know of an app that will provide a jack input source and send the stream to a different alsa hw output to the device that jack is connected to? What I would like to do is use my notebooks onboard stereo audio device as a headphone monitor output and my 4 port usb device as the jack i/o device. I don't really want to combine the 2 devices into a single alsa device. If no one has already written something for this purpose, apart from the obvious issue of samples potentially getting out of sync is there any other reason this combination may not work? Cheers. -- Patrick Shirkey Boost Hardware Ltd