Unable to mark rows to be updated in VBCS Excel Macro

Hello ,

We have a requirement to automatically copy the values of one of parent table's column to child table's column. Inorder to achieve this requirement i have written below function and it is called in preupload macro.

While the function copies the value from parent to child before uploading the data , but it does not mark the child rows to be updated. I have assigned the value as "Update" (highlighted in bold) to the first column and i could see it too appears in the excel sheet, but the child table changes are not saved and there are no errors too.