You are not a dumbo. I am the dumbo for assuming that everyone knows how to access certain things. In order to have this code work for your workbook you will need to do the following.

When your workbook is open press ALT + F11 This will open up the Visual Basic Editor
The Visual Basic Editor VBE is where code goes. On the left of this screen you will see some small Icons saying Sheet1, Sheet2, Sheet3 Or whatever your worksheets are called. and one called ThisWorkbook.
Double click on ThisWorkbook and you will see 2 dropdown lists above the white background editor. Click the one to the left and select Workbook. Then click the one to the right and select Open.

Some code will automatically fill in to the white background. Clear this out and then paste in the code I provided you. Save your workbook as a backup and then it should run everytime the workbook is open.

If you have issues with Excel saying Macros are disabled let me know and I will guide you through on how to fix that for the version of Excel you are using. You can find a lot of guides out there on the internet if you dont want to wait.

Let me know how it goes.

Thanks