NOP is entirely correct. The *.APA file is an RSView Studio archive, which includes the graphics, database, macro, alarm, and configuration files for an RSView Machine Edition project.
It can only be un-archived into the local FactoryTalk directory by the RSView "Application Manager" utility. Then it can be opened by RSView Studio.
If you don't have these tools, call Rexcel or the Rockwell Automation office in Orlando, and I'm sure one of their technical people can help you get a runtime or hardcopy of your screens generated.