Help with Guess Values and Trim part of Title


I am using the following Guess Values action:

Source format: %_path%
Guessing pattern: %dummy%\%dummy%\%dummy%\%dummy%\%contentgroup%\%dummy%_%title% - %artist%\%dummy%_%subtitle%_%dummy%

And would like to know if it is possible to trim part of the %subtitle% tag to keep only the part in CAPS.
eg: trim Mist Of Lies STEMS MELODY to STEMS MELODY

You would have to prepare the source pattern so that it is clear which part of the data should end up in the matching format string.
But I would run a second action that does the trimming.
$regexp('Mist Of Lies STEMS MELODY ','(.*?) (\u\u+ )',$2) leads to STEMS MELODY


is the filename part of the pattern
an example filename is ES_Mist Of Lies STEMS MELODY_PN.ext

I was actually wanting to automatically trim the part in caps to place in the %subtitle%, or if not possible... add the entire string between the underscores of the filename to %subtitle% and trim inside the tag.

I did not want to have to specify the filename in the action, as I am using an action group and there are over 1000 files I am trying to bulk process.

And? did you add my suggestion to your action group and dd it work?
If you treat SUBTITLE then

would become
$regexp(%subtitle%,'(.*?) (\u\u+ )',$2)