Thank you for the swift answer.
Note that my code skills are very limited and I don’t catch all the meaning of your comments.
Actually, I tried to implement it through a partial (not a shortcode) and the partial doesn’t work.
I have no idea of what you are talking of about transform.Unmarshal. I am going through the Hugo Forum to understand the feature. I found this post in the forum dealing with something similar but still unclear for me.
I am still stuck !