加序号

老版本公式
=1&SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(E19,"、","、5",4),"、","、4",3),"、","、3",2),"、","、2",1)
太多了就不好搞了，

=TEXTJOIN("、",,ROW(INDIRECT("1:"&(1+LEN(A1)-LEN(SUBSTITUTE(A1,"、","")))))&FILTERXML("<a><b>"&SUBSTITUTE(A1,"、","</b><b>")&"</b></a>","a/b"))

Power Query

如果是像我这样日期型的，长度一样的可以用这个（因为用的mac没有filterxml函数），因为日期长度是10。
2023-06-30,2022-09-09 变成：(1)2023-06-30,(2)2022-09-09
=TEXTJOIN(",",,"("&ROW(INDIRECT("1:"&(1+LEN(D6)-LEN(SUBSTITUTE(D6,",","")))))&")"&MID(SUBSTITUTE(D6,",",""),1+10*(ROW(INDIRECT("1:"&(1+LEN(D6)-LEN(SUBSTITUTE(D6,",","")))))-1),10*ROW(INDIRECT("1:"&(1+LEN(D6)-LEN(SUBSTITUTE(D6,",","")))))))

Option Explicit
Sub abc()
　Dim a, i, j, t
　a = [a1].CurrentRegion.Offset(1).Resize(, 1).Value
　For i = 1 To UBound(a) - 1
　　t = Split(a(i, 1), "、")
　　For j = 0 To UBound(t)
　　　t(j) = j + 1 & t(j)
　　Next
　　a(i, 1) = Join(t, "、")
　Next
　[b2].Resize(UBound(a) - 1) = a
End Sub