Look at page definition queries in Data Driven Pages. I would Google on ArcGIS Page Definition queries but here's one link: http://resources.arcgis.com/en/help/main/10.1/index.html#//00s50000002z000000Not knowing your particular situation I'll guess you would have an index layer of 400 features and a field added to it and to your polygon layer with a unique value for each one. It might take a little while to set up but using copy and paste methods it might not be bad. Once set up it's a piece of cake to use.If you don't want to do that you might look at Arcpy and combine that with DDP/