Yes, it is definitely possible to create a button that generates a random number in Excel. Here are the steps to set it up:

1. First, you need to enable the Developer tab in Excel. To do this, go to File Options Customize Ribbon. In the right-hand column, check the box next to "Developer" and click OK.
2. Once the Developer tab is enabled, click on it and select "Insert" from the Controls group.
3. In the "Form Controls" section, select the "Button" option.
4. Click and drag on the worksheet to create the button.
5. Right-click on the button and select "Assign Macro".
6. In the "Assign Macro" dialog box, click on the "New" button to create a new macro.
7. In the Visual Basic Editor window that opens, enter the following code:
   
   
   Formula:

   Sub GenerateRandomNumber()
    Range("A1").Value = Int((999999 - 100000 + 1) * Rnd + 100000)
End Sub 

   This code generates a random number between 100000 and 999999 and puts it in cell A1. You can change the cell reference to whatever cell you want to use for the ID number.
   
8. Close the Visual Basic Editor window and click "OK" in the "Assign Macro" dialog box.
9. Test the button by clicking on it. It should generate a random number in the designated cell.

That's it! You now have a button that generates a random number in Excel. You can customize the code to generate a different range of numbers or to put the number in a different cell if needed.