Convert write-in product into existing product

I would like to find a way to take a write-in product entered into a quote and make it become an existing product from that point forward. Similar to how entering in a lead creates a new contact. 

My company makes many custom products in addition to standard products. Because of this we utilize the write-in product feature. Occasionally the custom product will be ordered again and would like to simply just select the custom item from the existing products, just like I would any other standard product.

Is this able to be done? If so, is it able to be done without code?