How to convert AAC to loseless audio ?

Hi,

I've purchased some album in iTunes store, and would like to burn CD-Audio to my car now. I know how to convert files, but - obviously - there's one thing that doesn't give me peace of mind.

I've purchased whole music album before I realized how iTunes works :/ So looks like all tracks has beed downloaded in AAC format, which isn't loseless. Now, I can change settings in CONVERT section to get any format (available) I want - like WAV - but hey... this is a clue... converting means using ORIGINAL file as a source. Original = means AAC, files in which format are already downloaded, and sit on my drive.

So there's COMPLETELY no reason to convert files from non-loseless format to loseless one, because all imperfections will be transferred into loseless format. In short: such "conversion" in this particular case would be something like extension only change (*.M4A to *.WAV), but quality remains at non-loseless level, altough coverted file would be put into loseless format.

All I want, is to - if somehow possible - re-download purchased files, but in some loseless format now - and only then I can convert them to WAV, which is easy transferable to AudioCD.

Question is: how to get these files in original quality, before iTunes converted them to M4A I've already purchased ?

P.S. Don't ask me questions do I hear the difference, PLEASE.

Cheers,

Martin