The matches comparison supports regular expressions. You can name captured parts of the text and reuse them as tags in an action.
Example: extract a series name
For filenames such as Example Show.S02E05.mkv, create an On File Load rule and compare Original Filename using matches:
('my_show'.+)[sS]('my_season'[0-9]+)[eE]('my_episode'[0-9]+)The named groups are my_show, my_season and my_episode. In an action, set the show field to:
{my_show}iFlicks turns this into a tag referring to the captured value. You can use the other captured values in appropriate actions too.
The named-group notation ('name'...) is specific to iFlicks and differs from the notation used by many regular-expression tools. Test a matching and a nonmatching filename before enabling the rule for a whole folder.