How do I insert COMPOSER's last name into filename?

Hi,

I have filenames like:

08 Carillon de Longpont.flac

and

1-08 Carillon de Longpont.flac

but need them to be like:

08 Vierne - Carillon de Longpont.flac

and

1-08 Vierne - Carillon de Longpont.flac

where the COMPOSER tag is "Louis Vierne". Composers can also be like "Nicolas Jaques Lemmens", so it's always the last name that I would like inserted.

Is there an elegant way to accomplish this, e.g. with Replace, please?

Managed to kludge this with an Action Group and a temporary tag. I'm very much a novice so there are no doubt neater ways but this seems to work with the above formats although not extensively tested.

Put composer and filename into temporary tag
Action type: Format value
Field: DUMMY
Format string: %composer% %_filename_ext%
Result: Louis Vierne 1-08 Carillon de Longpont.flac

Discard composer first name(s)
Action type: Replace with regular expression
Field: DUMMY
Regular expression: (.)\s(.+\s(\d-)?\d{2}\s.)
Replace matches with: $2
Case-sensitive comparison: [ ]
Result: Vierne 1-08 Carillon de Longpont.flac

Swap positions of composer last name and disc-track number, adding hyphen
Action type: Replace with regular expression
Field: DUMMY
Regular expression: (.*)\s((\d-)?\d{2})\s(.+)
Replace matches with: $2 $1 - $4
Case-sensitive comparison: [ ]
Result: 1-08 Vierne - Carillon de Longpont.flac

Update filename from dummy tag
Action type: Format value
Field: _FILENAME
Format string: %dummy%

Clean up
Action type: Remove fields
Fields to remove: DUMMY