Import Subcontract Line Items from Excel

In order to set up a schedule of values for a Subcontractor to submit pay apps through portal, it appears you have to manually change or expand their subcontract line items. Right now, I award subcontract that is 2 or 3 line items, but these same line items are used for the portal sub invoice submission, so i have to edit these - usually during the subcontractor's first draw, and there is no way to import from excel that I can find, so it takes a lot of time to enter them.