Hello,
I think the main problem isn't the prefix; Lyrik try to get the tag (artist, album, title, etc) metadata first and then try by file playlist name.
If your file is been recognized as '
http://edna:69/English/U/U2/filename.mp3' that mp3 have no tags, without tags is a quite impossible to get the correct lyric.
If is it an radio, try to put tags on the stream, mainly radio plugins haves that option.
See ya,