COMPOSER tagging and viewing

[Donuk]

Thanks to both Stefano and Simbun for your answers.
I think I understand them both except Simbun's
"What you'd need to do is to create a new tag based on the value of HD in the Comment/#AudioQuality tag, something like:
Code:
@COMMENT=HD
+HDCONTENT=HD"
I can understand this code, but I can't see where I create a new tag, and should the Code be all in one line? In other words, where do I stick this.??
Sorry to be stupid. Any other forum and I would be dead by now.
Donuk