Create a filter to capitalize a certain file extension?

I use a program called QuickSFV that scans a file's contents, then creates a file with a .sfv extension, which contains a CRC32 hash. I can then double-click on the .sfv file, which makes QuickSFV scan the file again and compare the value stored in the .sfv file with what the current scan's hash is. The output file (.sfv) that is created is always lower-case.

The .sfv file creation looks like this:

While I can edit the .sfv extension at this point, so it is capitalized, I would like to create a filter or a script that will automatically capitalize the lower-case .sfv extension after the .sfv file is created, so it is changed to .SFV. This script or filter needs to ignore the .sfv extension if it is already capitalized. Thank you for any help.

QuickSFV homepage:

NOTE: I use QuickSFV to confirm that a file I have confirmed is clean and has not been corrupted or changed (for files without a digital signature).

There's no way to make Opus pretend the extension is .SFV when it's really .sfv (well, short of writing a VFS plugin, which would be a huge amount of effort for something like this).

You can make Opus rename *.sfv to *.SFV easily enough, and could e.g. make a button which runs QuickSFV and then renames the files in the place(s) it was expected to put them.