Thank you guys! I figured it out. For anyone looking for the same; here's what I figured out:
Today, most laptop screens use a 30-pin eDP connection. If you would like to use this for one of your projects, you need a controller board for that specific screen. This will give you an HDMI input - which you can use with your Raspberry Pi 3 HDMI output.
For example:
http://www.ebay.com/itm/Novatech-L-Seri ... Swo4pYgjlR
This laptop screen is named B154EW01 - to find a suitable controller board, we have to search for: "B154EW01 Controller Board".
http://www.ebay.com/itm/VGA-LCD-Control ... SwcUBYSQ9M
Hope this was helpful for someone!
Good luck!
- PlayableCharacterX