以下的宏代码，其功能是，找到AB两列相同值，并存放到C列。
Sub MySubSearch()
Dim i As Integer
Dim c As Range
For i = 2 To Sheet1.[B65536].End(xlUp).Row
For Each c In Sheet1.Range("A2:A" & Sheet1.[A65536].End(xlUp).Row)
If Cells(i, 2).Value = c Then Cells(i, 2).Font.ColorIndex = 3
Next c
If Cells(i, 2).Font.ColorIndex = 3 Then _
Cells(Sheet1.[C65536].End(xlUp).Row + 1, 3).Value = Cells(i, 2).Value
Next i
MsgBox "所有重复编号已经找出，请查看结果！"
End Sub