Excel formula 区分大小写的首次出现突出显示

我有一个区分大小写的列&有重复项，我想突出显示每个值的第一次出现

对于区分大小写的副本，我使用以下公式给出了从1到n的数字

=IF(EXACT(A$2:A$3564,A2),COUNTIF(A$2:A2,A2))

这几乎适用于所有记录，但当我遇到下面这样的记录时，它无法正确指示数字

0031Y00004remsw_Alistair Laycock
0031Y00004remsW_Alistair Laycock
0031Y00004remsw_Alistair Laycock
0031Y00004remsW_Alistair Laycock
0031Y00004remtm_Alistair Laycock
0031Y00004remtM_Alistair Laycock
0031Y00004remtm_Alistair Laycock
0031Y00004remtM_Alistair Laycock

以下是此类情况下的结果

0031Y00004remsw_Alistair Laycock     1
0031Y00004remsW_Alistair Laycock     2
0031Y00004remsw_Alistair Laycock     3
0031Y00004remsW_Alistair Laycock     4
0031Y00004remtm_Alistair Laycock     1
0031Y00004remtM_Alistair Laycock     2
0031Y00004remtm_Alistair Laycock     3
0031Y00004remtM_Alistair Laycock     4

所需的输出如下所示：-

0031Y00004remsw_Alistair Laycock     1
0031Y00004remsW_Alistair Laycock     1   'This being first Occurance with "w" 
                                          in capital'
0031Y00004remsw_Alistair Laycock     2   'This being second Occurance with "w" 
                                          in small'
0031Y00004remsW_Alistair Laycock     2
0031Y00004remtm_Alistair Laycock     1
0031Y00004remtM_Alistair Laycock     1
0031Y00004remtm_Alistair Laycock     2
0031Y00004remtM_Alistair Laycock     2

如有任何建议/帮助，将不胜感激

这个怎么样

=SUMPRODUCT((--EXACT(A2,$A$2:A2)))