I dunno how to help you, but I'll rephrase what you posted so that maybe someone else who knows a little more about what you need can understand it better.
" I have a campaign that has 4 256x256 maps. I was wondering if I can have around 60 maps within this campaign and have the hero progress through the different maps. "
I'll try to help out anyway...
I think you have to use Game Cache, but I don't know how to use it. It pretty much makes a file that saves the heroes progress, and can bring the stats, items of the hero to another map. Take a look at the Game Cache section in WorldEdit.