以下是实现该功能的VBA代码:
```
Sub CompareColumns()
Dim lastRow As Long
Dim colCount As Integer
Dim i As Integer, j As Integer, k As Integer
Dim diffCount As Integer
'获取最后一行和列数
lastRow = ActiveSheet.Cells(Rows.Count, 1).End(xlUp).Row
colCount = ActiveSheet.UsedRange.Columns.Count
'在最右侧添加一个空白列
ActiveSheet.Cells(1, colCount + 1).Value = "差异数量"
'循环遍历每两列信息
For i = 1 To colCount - 1 Step 2
For j = 1 To lastRow
'比对两列信息的逐行字符内容
diffCount = 0
For k = 1 To Len(ActiveSheet.Cells(j, i).Value)
If Mid(ActiveSheet.Cells(j, i).Value, k, 1) <> Mid(ActiveSheet.Cells(j, i + 1).Value, k, 1) Then
diffCount = diffCount + 1
Exit For '只算有一个字符的差异
End If
Next k
'将统计结果生成在最右侧的空白列
ActiveSheet.Cells(j, colCount + 1).Value = diffCount
Next j
Next i
End Sub
```
使用方法:
1. 打开Excel文件,按下Alt+F11键打开VBA编辑器;
2. 在左侧的项目窗口中双击需要添加代码的工作表;
3. 将以上代码复制粘贴到右侧的代码窗口中;
4. 按下F5键运行代码即可。