Cannot add a custom field to order lines

Cannot add a custom field to order lines

Hello and best compliments for this great software application!

I am almost set with basic configuration for orders, but would like to add a custom field to the order line, just imagine a free additional description or a comment that will differ from item to item. I cannot add a custom field, since it will only show at "header" level.

example

product XXX qty 10 price 10 total 100 description "special colours"
product YYY qty 1 price 100 total 100 description "special offer"

Any clue on this? Thanks in advance.

Paolo