If you talking about the barrel adjustment to tighten/loosen the cable tension....on the rear derailleur it should be where the cable enters the derailleur. My campy ones are on the cable stops on my down tube. There are some good videos on the net for derailleur adjustments if you do a search. One of the meanings of the name Erik is 'forever strong'
‘The negative feelings we all have can be addictive…just as the positive…it’s up to
us to decide which ones we want to choose and feed”… Pema Chodron