There's a dream-like quality to your question coupled with a certain lack of realism to say nothing of its lack of clarity.
It may be best to enter another question with a bit more detail and include the make & model of your CD Player for instance.
Describe the shape of the plastic part and say where you think it may have come from - even if you have to guess. Tell how the player now behaves without the part in place - a big clue.
Do not expect anybody to direct you to an assembly drawing - a very very slim chance.
Good luck...
Peccavi, April 2013
