ExtractRegex #

Extract a regexp result. Stores an empty string if not found.

[[step]]
    action = "ExtractRegex"
    label = "mytag"
    search = "^CT(..)CT"
    replacement = "$1"  # standard regex replacement syntax
    segment = "read1" # Any of your input segments

This transformation searches for a regular expression pattern in the specified read and extracts the matching portion as a tag.