@lgsalmon we do have the option to attach the same receipt to multiple expense entries, but it must be activate for your site. It is activated by going to Administration>Expense Admin>Site Settings. It is the last option on the Site Settings.
However, if it is not activated and you have a copy of the receipt saved on your computer, you can just reuse that image as many times as you need. When you go into each entry and use the attach receipt option, you can browse for the image each time because it is saved locally on your computer, not in SAP Concur.
The option I referred to will keep a copy of the image in Available Receipts instead of removing it once attached to an entry.
Let me know if you have any questions.