Creation of a sum Loop from the bottom down - VBA - Excel - excel

Question

Hello Stack overflow community and thanks in advance for all the help you could give me.
I am currently trying to create a loop to go through a column and create a sum of the data that is below that till the next blank line and in the next blank line create a new sum again doing the same process till that we get to two blanks following each other.
The below code does something similar but in the sum is upward and not downward.
Would anybody have a solution? Thanks a million for your help.
Dim cell As Range
Dim offset_rows As Long
Set cell = Range("O2")
Do While Not IsEmpty(cell.Offset(1, 0))
offset_rows = Range(cell, cell.End(xlDown)).Rows.Count - 1
Set cell = cell.End(xlDown).Offset(1, 0)
'cell.FormulaR1C1 = "=SUM(R[-" & offset_rows & "]C:R[-1]C)"
cell.FormulaR1C1 = "=SUM(R[" & offset_rows & "]C:R[1]C)"
Loop

Answer 1

I slightly tweaked the macro and it does now the sum downward.
Thanks again so much for your help, really appreciate it!
Sub SumRowsAbove()
Dim StartRow As Long
Dim SumRow As Long
Dim lRow As Long
Dim LastRow As Long
Dim BlankRowsCtr As Integer
Dim FormulaRow As Integer
' modify to your sheet name
With Sheets("Macroprep")
' find last row with data in column "O"
LastRow = .Cells(.Rows.Count, "O").End(xlUp).Row
StartRow = 3
BlankRowsCtr = 0
For lRow = 2 To LastRow + 1
If Not IsEmpty(.Cells(lRow, "O")) Then
SumRow = lRow
BlankRowsCtr = 0
Else
BlankRowsCtr = BlankRowsCtr + 1
' if 2 or more rows are empty >> exit sub
If BlankRowsCtr >= 2 Then Exit Sub
FormulaRow = StartRow - 1
.Cells(FormulaRow, "O").Formula = "=SUM(O" & StartRow & ":O" & SumRow & ")"
StartRow = lRow + 1
End If
Next lRow
End With
End Sub