You can not do this in WotLK. The source you provided is based on some newer expansion (the way I noticed this is by seeing1h duration of Water Shield on one of the pictures). While the conception is same there are some features added in Grid2 later. I don't know how to explain it correctly but the thing is in WotLK the way absorbtion effects are coded and read by the game is really weird. There is no real tooltip of the absorbtion buff with amount of actual absorbtion so there is nowhere for Grid2 to read this information. For healing spells I believe this is possible but not for absorbing.
For health (if I understand you correctly) you have to make an indicator with type "text" and then enable in this indicator "health-current".