Edit Product description on Draft Order (Create Order) page

[TimiAdler]

We are selling custom-size materials, so I would need to create about 20,000 variants to cover all. 
I would like to use only one product that refers to 1 square foot of material and use the quantity for the total square foot to multiply the cost and weight. In order to handle it this way, I should also add the dimensions to the description, such as:

Quantity:4500

Default description: 

Description for the actual order: Greenhouse cover, 1 square foot, total 50'x80'

Is there an app or other solution to edit the description this way? 

Any help is much appreciated!

Timea