Not an easy project. There is no way you can use the laptop LCD as your desktops primary display without jumping through a few hoops first.
This is what a typical LCD screen uses for power and data signal input.
This is what your typical desktop graphics output ports look like.
In anycase, you've left out a LOT of important details needed to answer your question.
Like... the laptop is still working OK, correct?
My advice is to bite the bullet and get a desktop LCD monitor for your desktop PC.