Hello Andre Gonzalez, I'm not sure to understand exacly what you need,
but to add some extra info to the recipient schema, you need to extend
the builtin nms:recipient schema :
https://experienceleague.adobe.com/docs/campaign-classic/using/configuring-campaign-classic/editing-schemas/extending-a-schema.html?lang=en#configuring-campaign-classicWhen
done, if you want to give access to the new attribute (or column),
you'll have to edit the associate form (nms:recipient), but be
carrefull, this form...