There's several options moving maps, depending on what it is you want to do. One is the Firaxis scenario editor itself - under File -> Import, you can import various parts of one BIQ/BIX/BIC into another (although you do have to look out for some things such as resources not lining up as expected afterwards). I've added similar, but BIQ-only at this point, functionality into my editor (link in sig), with advantages such as lining up resources by name, and disadvantages such as not being able to import non-map parts of a BIQ. There's probably a couple other options out there as well.