Hi! I got few questions because i stuck.

On the beginning i describe problem and what i want achieve.

I got odoo instance which synchronize with magento2, mostly products, customers, order etc. I add to my products field old_code(old sku product). I want import only this one field to odoo but when i try import this field i can saw that other fields like description, price chnage to null because i had only 3 fields default_code, old_code, name. In magento2 i haven't this field old_code co and i prefer import only this values to odoo. I want make button which can open a wizard window or something like that and upload csv file and after all python code update or create old_code for default_code product. I don't know how can i make this button and view. I show screen where i want add button. It's a kanban view product template.

https://ibb.co/HDN8mpw

Above is shown the place where i want add button.

Can you help me, give some advices or describe how can i make this. Maybe is other way to import products and only updates fields without change oher field to null, 

I hope someone can help me.