The AA script that comes with Extended Services cannot be modified. You will need to purchase a CRS license. I have heard of a way to be able to upload ned scripts with Extended Services, but never actually done it nor attempted to figure it out. If you have Unity you are probably better off with it if you need to dial by name, as CRS spells the names back to you as oppose to actually saying it. It really depends on what you need to do in your AA, I had an installation where I needed to use CRS because the dial plan was 7 digit, but callers had to enter only 4 digits. With CRS I was able to prefix the other 3 digits, there is no way to accomplish this in Unity.
Chris