I am not sure, you would need to experiment with that idea. Playlists created in LW can definitely be opened by other players that utilise playlists.

If you are still having a problem with a few music files not going into iTunes, try opening them with another player to be sure they play ok.

Also are you sure only 224 songs have gone to iTunes? There might be another reason for this such as the song name that appears in iTunes is different to the file name. Check the most recently added songs playlist to check this.
Also, maybe some of the songs you downloaded are identical to some others but have a slightly different name.

Keep in mind iTunes can only import mp3, m4a/mp4, aif, wav, & apple lossless audio formats.