Maybe a dumb question, but: Why are 'placeholders' not just functions?
In most scripting languages the placeholder variables would be function calls - $file_size(), $extension(), $bitrate(), for example.
This question occurred to me reading a recent thread about numbering files and getting the total number of files. There doesn't appear to be a 'placeholder' or a scripting function that would be helpful in creating a 'n of m' numbering for a file, and that total can only be entered manually when using the auto-numbering wizard.
May I suggest a function that could be used in scripts that counts the total number of files in the same folder?
Pass in the extension, or maybe use a windows wildcard.
For the most people this would be the total number of files in an album (or on a disc).