identifying aac+ songs

[seyss]

Hello,

I wanna enable that iTunes Match thing but iTunes won't recognize aac+ songs, so I'd like to transcode them with Winamp.

However I can't seem to easily identify which songs are in aac+ in the Winamp Library.
I can show the file extension, but aac+ files has the same .aac extension as regular aac songs.

What should I do?

Thanks.