Match, Find, Offset & Sum in loop not working

[DeanP]

In my worksheet my data is exactly as shown in attachment.

For very cell in col R7 to end <> 0, I want to find the first occurrence of the value of Col O7 to End In Col D7 To End.
Then using offset or similar I want the value of the cell one row below and 5 columns to the right of col D (so for D7 the value in I8,
for D26 the value in I27 etc) to be the sum of it's value and the value in col R.

In my data for the first 4 rows in col R, columns I8 = 8323.91, I27 = 37.13, I46 = 12.59 & I65 = 810.79

So far I've got this code

Dim DRow As Long
    DRow = Cells.Find("*", SearchOrder:=xlByRows, SearchDirection:=xlPrevious).Row
    Dim Brng As Range
    Dim foundcell As Range
    For Each Brng In Range("R7:R" & DRow)
        Set foundcell = Range("D7:D" & DRow).Find(Brng, LookIn:=xlValues, LookAt:=xlWhole)
        If Not foundcell Is Nothing Then
            Cells(foundcell.Row, "I") = rng
        End If
    Next rng

I'm not even sure this will be worth anything because I'm stuck here. Any advice would be appreciated.