Updating excel sheet for repeated row values

from the sample data not all is clear but in general you can doit with grouping the data on first col and memorizing the row index

with following Flow / LINQ you can also create a helper structure.

  • readin your excel with a read range - dtData
  • prepare the the helper datatable by:
    dtHelper = dtData.Clone
  • add a Datacolumn on the end: ColumnName = idx
  • Assign activity and a LINQ / or For each row on dtData - Fillup dtResult along with rowindex info

Grouping the data:
Assign activity:
Left: Result | DataType: List(Of List(Of DataRow)) - outerList: the groups, inner List: the group members
Right:
(From d in dtHelper.AsEnumerable
Group d by k=d(0).toString.Trim into grp=Group
Select g=grp.ToList)

Now you can iterate over groups by a for each activity | TypeArgument is: List(Of DataRow)
Within the Body Block you can do the corrections / processings on the group & members
With the help of the idx Column you can access the data in dtData or can use it for updating in Excel.

We can suggest to do the entire updates on dtData and then overwrite /write to a new Sheet to Excel