The first thing that comes to mind is XL Reporter. This automatically does exactly what you want: periodically saves PLC data into spreadsheets.
The other way to do it is more manual, but it still requires RSLinx Gateway or some other OPC server. You can copy references to live OPC tags directly into excel using the following procedure:
In RSLinx, click the Edit menu, then "Copy DDE/OPC Link." Select your processor and address in the dialog box and click OK.
Then in Excel, find the "Paste Special" command. Click "Paste Link" and then ensure "Unicode Text" is selected. The value in the address is now in your excel sheet. However, this only works with live values. If you want to do more, you'll need to write some custom VB code and embed it in your spreadsheet. Probably some button that copies the current values of the cell(s) with the OPC links to different cells and then build your report from that. You could probably even script it so that Windows periodically opens Excel, runs the VB code, and saves it off into a different file. Don't ask me how though, I have no idea where to start with that.
If you want any kind of automated data logging, put "cheap" out of your vocabulary right now. Either you pay for a package like XL Reporter, or you will spend more money in time and effort reinventing the wheel to make your own custom solution. Even with my "cheap" method above, you're still paying for an OPC server of some kind.