Use Add from Discogs under album.

1) Search in the Add albums from discogs box using artist or keyword (use album title here)
2) Select the entry that matches your cd release code (discogs usually has several entries for any album)
3) Might also check for which discogs entry has the best credits, musician and recording data (discogs is much better on this than freedb)
4) Change the format to CD if it isn't that already
5) Under the Misc tab add the album path

I was using this even when freedb was still available as discogs provides more - and more accurate - information than freedb