I suggest add dialog similar to the "Replace in Files..." dialog for macros. It can apply a macro to files.

A dialog like "apply macro to files..." will make it simpler to write the macro.

Aslo I suggest create a arugments object parse a user input string into arguments. And allow passing arguments to macro.

I changed my mind, for batch jobs that are not related to EmEditor window or current editing documents, it is better to use a tool particular for macro/scripting to do that (such as AutoHotKey). So please ignore my post above.