If I want to capitalize first word ("first" in following example) in a filename which is numbered e.g. "01 - first file.ext", the only option is to use script, right ?
No, you can use the Modify Capitalization -> Capitalize First Word option for that.
Look at this post
Are regular expressions out of question?
Regular expressions can't change the case of things, so they won't be enough on their own.
We can help write simple rename scripts, if needed, with a bit more information on what you want.
For these inputs, what do you want the outputs to be?
- 01 - first file.ext
- 01 - FIRST FILE.EXT
- Files from this PC.txt