Linking worksheets without using the full file path

Hey Guys,

I have a workbook with multiple sheets. Each sheet represents a purchase order with a supplier, together with a summary sheet that I use to control payment for the individual purchase orders.  My summary sheet is linked to the payment total and tax total on each purchase order.

Each week I need to reconcile the purchase orders for that week.  If I copy my summary sheet from the week prior, all of the links refer to the full file path (eg, they still reference the previous week's purchase orders) and I have to manually go through an relink them to that week's purchase orders.

All the tab names are always exactly the same from week to week.

How do I get the link to reference the tab in that same workbook, rather than the the tab on the previous week's workbook?