Add Log Fields to first log "... execution started"

Curious to know how “… execution started” and “…execution ended” logs are added by UiRobot.
I have a requirement to add custom log field, and when I added this field with the help of “Add Log Fields Activity” in Init State, custom log field is visible in all the log messages except “… execution started” message.

@ronlobo If you are familiar with text file means in the beginning of the bot use write to text file and pass value with current date and time and in the end use append line and pass current date and time.