if you have nero 6.x, nero soundtrax can do it. just click 'insert' > 'audio file', select the tracks, accept the order and then when its loaded the tracks click 'file' > 'export to audio file...'. then you can use the 'save as' dropdown to select the desired format.
i had a better, lengther explanation but when i posted it in ot it said the thread was locked and i lost what i wrote.