Merge quotes

Question is there a way to merge quote’s together.

Why?
We have customers like Ikea for example, and we make always seperate quote.
Than this quotes need to be approved by some person and after that i get a “Purchase order” from IKEA.

the problem is they merge all the quotes together and then they make 1 Purchasorder number for all the quotes.

I may only make one Invoice with that purchaseorder number.
So if there is a way to merge the quotes together, i can simply convert the merged quotes to 1 invoice.