daily workout remaining time data field

I would like to create a data screen which shows three fields:

  • current HR
  • ETE
  • time remaining of my workout (coming from the Daily Workout)

At first one might think of two possible approaches:

  • edit the data field of the special daily workout data screen, as that already shows the remaining workout time. Just another field should be changed to ETE. As far as I know this is not possible
  • edit a normal data screen to show these parameters. However I cannot find the "time remaining of my workout" field anywhere, when editing a data screen