Thanks for your question, which has come up in earlier topics:
rename filenames in bulk with chronologically numbers?
As I explained in that topic, MLA does not have any file name renaming features and I have no plans to add them. There are other plugins for this task, such as the plugin used by another MLA user:
How to add a number to the title of images inserted in same post?
I am marking this topic resolved because the question has been answered. I regret that MLA will not help you with your file renamins task, but I hope you understand my reasoning. Thanks for your interest in the plugin.