Can Robocopy be configured to only log the “errors”?
On a large copy job, I’m really only interested in knowing what files were NOT copied.
It's not in the documentation that you can do this;
What you could do is run your job with /v and output to a logfile /log: then write a small script to parse the log file and remove all but skipped files.
There's a nice looking script here;
This will parse the log file (check the switches) and then output to a CSV which you could easily manipulate in your favorite spreadsheet program.