According to cover.info this work is derived from 'Santiano / Santy Anno / Aweigh, Santy Ano / Santy Ano / Santo Anno'. The rootwork is in our database represented by Santianna and has 19 different versions and adaptations in Czech, Dutch and French.
GEMA gives for Holm's Santiago indeed also Moroder as co-composer, but I cannot quite hear what he added to the tune.......... So add a German adaptation to the root work.
Thom