Linking by contents not by cell number in Excel

Hello,
I currently have two workbooks open on excel. One is a shipping list of spare parts that I have sent out and the other is the one I use to keep track of my inventory.

The shipping workbook is organized by the date in which the part was sent out, I can't organize it in any other way, and my inventory workbook is organized by part number. I would like to link them so that when I ship out an item, it automatically updates my inventory workbook.

How can I do this? The only solution I have found is linking cells but the cell numbers change all of the time depending on how parts get shipped out. I would like for the lists to work by cell contents (part numbers) and not by cell numbers.

Thank you!