Searching inside comment field (Advanced Search) doesn't seem to work

Hello,

I've been searching for a solution to this and have been unable to find a way to make this happen.

I'd like to be able to search the comment tags of my music files for phrases like "jamendo", "magnatune" or "bandcamp" to find music purchased or downloaded from these music sites. Unfortunately the Squeezebox server doesn't appear to match these if they're in a url like "http://magnatune.com/artist/foo".

Is there a way to do a wildcard search so I can type something like "%magnatune%" and have it find phrases inside of a piece of text?

Thanks!