You'll need a rename script.
%appdata%\GPSoftware\Directory Opus\Rename Presets
JScript
// https://resource.dopus.com/t/rename-each-word-starting-with-a-capital-but-excluding-specified-words/49637
function OnGetCustomFields(getFieldData) {
getFieldData.fields.alwaysLC = '';
getFieldData.fields.alwaysLC.label = 'Lower Case';
getFieldData.fields.alwaysLC.tip = 'Enter words that are always in lower case';
getFieldData.fields.alwaysUC = '';
getFieldData.fields.alwaysUC.label = 'Upper Case';
getFieldData.fields.alwaysUC.tip = 'Enter words that are always in upper case';
}
function OnGetNewName(getNewNameData) {
var alwaysLC = getNewNameData.custom.alwaysLC;
var alwaysUC = getNewNameData.custom.alwaysUC;
var testLC = ' ' + alwaysLC.toLowerCase().replace(/[^a-z ]/g, '') + ' ';
var testUC = ' ' + alwaysUC.toLowerCase().replace(/[^a-z ]/g, '') + ' ';
var allWords = getNewNameData.newname_stem.split(' ');
for (var i = 0; i < allWords.length; i++) {
var test = ' ' + allWords[i].toLowerCase().replace(/[^a-z]/g, '') + ' ';
if (testLC.indexOf(test) >= 0) {
allWords[i] = allWords[i].toLowerCase();
}
if (testUC.indexOf(test) >= 0) {
allWords[i] = allWords[i].toUpperCase();
}
}
return allWords.join(' ') + getNewNameData.newname_ext;
}