To add a particular EI in Project Invoice

Summary: To add a particular EI in project invoice once the Draft is generated

Content (required): We have a requirement where in business generate a draft project invoice with particular bill through date post which the they need add particular EI's (Lets say recently imported supplier cost).

Now when a business run the generate invoice process include all the eligible Expenditure item for invoicing but here they want add only few EI to be add in the invoice. I know we can add through manual invoice line on invoice but when we follow this invoice format and contract line doesn't update on the project invoice due which receivable accounting is fails as accounting source defined based contract line number.