Hi @ignacio, not sure exactly what you are trying to do here. By host, do you mean the website's base url and the id being the PK of that website in your table?
Regardless, I'm pretty sure you could do a JS Query to transform the data from the csv and attach the id_product and customigna in the data object of the JS Query before putting it on the table. With this complexity, I don't think going straight to custom column is a good idea.
Hey @ignacio, This is possible! Assuming that your CSV data is formatted as an array of objects, you can write a script in a JS Query to iterate through your data and trigger a separate query with the host value for each row and append that value to your dataset. You can pass the host value to the query you trigger with additionalScope. Here are a couple of examples of ways you could trigger these queries for each row in your data.