Thanks for the clarification, PG.
I am ideally looking to open .m4a lossy and lossless formats to AIFF/WAV etc in Wavelab/64. Sometimes I only need to do one, sometimes a whole batch. Currently I have to switch to WL8/32 to do this.
iTunes can currently be used to batch convert to WAV/AIFF (at the minor inconvenience of adding all the new files to the library, whether you want them there or not). But I would really like to be able to open these files natively in Wavelab 64 bit, not least because I (perhaps unnecessarily) wonder if apple will one day remove this functionality from iTunes without warning!