Leaderhead expressions?

[Maxor127]

I'm interested in creating my own set of leaderheads that would change to convey different expressions depending on their attitude with the civ they are speaking with. I'm not looking for anything fancy right now, just showing a different still image depending on the foreign relations. Also, I'm still trying to find out if there's a way to assign a certain leaderhead image to certain eras like Civ 3 only just by changing the .dds of the leaderhead during each new era.