Hi.

I'm trying to assign ownership of a cell through a quest script.

Could someone direct me to a previously existing example of this?

How could I implement this?

http://geck.gamesas.com/index.php?title=SetCellOwnership.

Assuming it's the player that is taking ownership of the cell, you won't write the faction and the script line will be:

SetCellOwnership rMyCell

Then you must decide when doing it, how doing it, what to do with the objects that don't inherit ownership from the cell etc. your question doesn't provide these elements.

I can't think to anything like that in vanilla.