I have a regex preset called "SUFFIX"
I bring up the command line and enter this command:
rename PRESET=''SUFFIX"
The rename dialog box appears but the "SUFFIX" preset is not selected.
Am I doing something wrong?
This works
rename ADVANCED PRESET="SUFFIX"
Not sure maybe I did a typo first time.
All good 
Rename PRESET=''SUFFIX" - That would try to run the preset on the selected files.
Rename ADVANCED PRESET=''SUFFIX" - Opens the advanced rename dialog with the preset selected.
Thank you Leo