Well, I've got these eyebrows from a sim (in .sims3pack) that I've donwloaded a long time ago, but I suppose that they were in .package file previously, since in my CC Installed list in launcher it's not shown. And I'd like to use it in a sim I've created and credit the creator correctly...

some days ago i saw a similar "creator is searching for cc since he/she wanted to link to it" request. so i started a thread at nraas how to find cc with master controller (and some other tools). maybe you want to take a look at that discussion (it is long!) since there are awesome tipps and tricks to search for cc filenames via ID. the discussion (chatterbox-english) is here: https://nraas.wikispaces.com/share/view/69017182
its not going to be easy and you need some tools/mods (master controller, integration, S3PE maybe debug enabler) but if you can get those methods to work it will be incredibly useful even in the future ;-)
tell me if you can read that thread (you should even as non member)- if not i would be honoured to make a copy-paste action of the mini-tutorials

also you can visit the other creators request thread here: http://modthesims.info/showthread.p...d=1#post4505562
BloodyScholastic was able to find the certain cc with one of the methods mentioned at the nraas forum

Yes, I can read that thread, I will try this one
But does it work if the cc is merged in the .sim file?

erm i doubt that. but you need to try. it will point you to that sim file i guess but then?
but if you know which sim that eyebrows set came with we (the helpers) have more details where to search. hopefully the sim has a cc list then