excel....點樣將2行比較?

例如: A___________________B
1______dd ltd______________dd ltd
2______dd ltd______________dd ltd
3______dd ltd______________ dd ltd
4______hi ltd______________ dd ltd
5______ka ltd______________ hi ltd
6______nn ltd______________me ltd
7______nn ltd______________me ltd
8______nn ltd______________nn ltd
9______nn ltd______________nn ltd
10_______________________ nn ltd

2行已經順英文字母排好....有冇辦法自動搵出2行既唔同??
即係B 多左一個dd ltd, B少左一個ka ltd, B多左2個me ltd, B少左一個nn ltd....
或者當發現2行唔同個時 自動向相對個行加一間空格....
即係:

________A________________B
1______dd ltd____________dd ltd
2______dd ltd____________dd ltd
3______dd ltd____________dd ltd
4_______________________dd ltd
5______hi ltd_____________hi ltd
6______ka ltd
7_______________________me ltd
8_______________________me ltd
9______nn ltd____________nn ltd
10_____nn ltd____________nn ltd
11_____nn ltd____________nn ltd
12_____nn ltd