The only way is by using that python script, or a complicated series of time-consuming commands

. Simply paste it into a text file, and save it as add-series-to-custom-column.py and then open a command prompt, type "cd \location\of\folder\goes\here\" (most likely your downloads folder

) and type "calibre-debug.exe add-series-to-custom-column.py"
Err, additionally you will have to enter the library path, and change the custom column to a suitable name, so I am uploading a modified python file (in a zipped folder, because we cannot upload .py files) that imports the path to your most recent library.

Use a custom column called "formatted_series", or edit the file to change it if you want.