Why is sort of hyperlinks in Excel hardcoded to cells?

We created a spreadsheets that contained hyperlinks. The hyperlinks worked
properly, but when the list was sorted and the hyperlinks were moved to new
rows, the hyperlinks did not link to the proper website. It was as though
the hyperlinks were hardcoded to the cells. The hyperlinks were created by
copying them from a webpage to an Excel spreadsheet. Any ideas on how to
correct this problem?