Using Spaces with long Documents to make related changes

I am working on a 300 page document (PHD thesis) in MS Word (Office 2004) and would like to have several sections open in different windows so that I can quickly makes changes that effect related sections. I was hoping to use Leopard spaces with different sections but don't know if it is possible and whether the changes would be saved to the one doc. Perhaps there is a different solution. Any other suggestions related to this help would be welcome.