Hi @kisirataibu
The part number for the base enclosure is [https://www.google.com/search?client=firefox-b-d&q=+646261-001|646261-001] (examples only).
There is no separate lid cover as such, as it is a part of a complete module which includes the display etc.
There are 6 different top covers available (where the keyboard is situated) but it depends on what features your particular laptop has as to which one you need. See item #3 on p.20 of the [http://h10032.www1.hp.com/ctg/Manual/c03054480.pdf|maintanance and service guide] for the laptop to find the part numbers of the part.
Search online for the ''part number only'' of the particular part that you're looking for, to find suppliers that suit you best.