Excel VBA突出显示工作簿中的重复项

I am trying to highlight duplicates across a workbook of 12 sheets. Essentially we are using it to track ID#s and I want to highlight the cell if this ID#(value) has already been listed on any of the other sheets. I was able to come up with the below code, but even when I use in the "This Workbook" it only applies it within a sheet, and not across the multiple sheets. I am trying to highlight duplicates across a wo