I solved a similiar problem this way:
I created a separate library for the music I listen to off of CDs, but this would not be necessary...I just think it makes it easier to differentiate.
Under Tools/Options/Tree & View I added a new Library Field named "Music & MP3 CD" with a data type of string and store file in tags turned off.
Then, I just imported the files from each CD into my library. When I imported the CD, in the above mentioned field, I put name of the CD.
To make it easier to find CDs and stuff, add the new library field to the Media Library/Audio fields and then save it to the current location and all sub locations.
Then, when you want to find a song, just search your library for a song and you have the disk it is on right there. Also, if you just want to play a disc, search that field for the disc name and then add the results to playing now (or make smartlists with the above field set to the desired name).
This process seems to work really well for me. Hopefully I explained it well enough.
Jiistme