How do you reference a variable file in VBA?

How can I reference Sheet2 of my opened file?

Currently I have a macro that finds the most recent file in a folder and opens it. If I wanted to do a calculation based on a column in Sheet 2 of the newly opened file, how would I reference this file in VBA? I cannot use the file name to call it since the file name will change (each time I run the macro, the most recent file is opened). For example, if I run the macro this week, the file name "12-7 Reports" is opened, but if I run it next week, the file "12-14 Reports is opened"