Hi, will tell you a method without using for each which can be used in any formula like we do drag drop in excel manually.
Use write cell. In the cell property use "E2: E".Trimend+(<your data table>. Rows.Count+1).tostring.(since your requirement starts from 2nd row here E2. IF from the first row only rows. Count)
In formula use the same,
"=sum(C2+D2)".
Confirm once it worked.