Opus' regex dialect doesn't support capitalization. But a rename script is not too difficult.
// https://resource.dopus.com/t/regexp-to-capitalize-all-words-in-filename-without-modifying-existing-camelcase-or-humpcase-words/46680
function OnGetNewName(getNewNameData) {
var allWords = getNewNameData.newname.split(' ');
for (var i = 0; i < allWords.length; i++) {
if (allWords[i].substring(1).match(/.*[A-Z].*/)) continue;
allWords[i] = allWords[i].substring(0, 1).toUpperCase() + allWords[i].substring(1);
}
return allWords.join(' ');
}
%appdata%\GPSoftware\Directory Opus\Rename Presets