Loop to replace values greater than 0 - excel

Question

Sorry I am a novice in VBA so any help is gratefully received!
I'm looking for some VBA code for a loop that will look at a range in Column A and as long as the cell in Column A is not 0, replace the adjacent cell in Column B with the positive value, looping through the range until all cells with data > 0 in Column A have been replaced in Column B. It is also important that blank cells in Column A do not overwrite positive data that may exist in Column B.
This is where I am at the moment:
Sub Verify()
Dim rng As Range
Dim i As Long
'Set the range in column N
Set rng = Range("N2:n1000")
For Each cell In rng
'test if cell = 0
If cell.Value <> 0 Then
'write value to adjacent cell
cell.Offset(0, -2).Value = *'What do I need here to find the first item of data e.g. N2 in column N?'*
End If
Next
End Sub
Many thanks

Answer 1

I think it would be easier to deal with ActiveSheet.Cells as with Range object and offsets :
Sub Verify()
Dim row As Long
For row = 2 To 1000
If ActiveSheet.Cells(row,1) <> "" Then ' Not blank
If ActiveSheet.Cells(row,1) > 0 Then ' Positive
ActiveSheet.Cells(row,2) = ActiveSheet.Cells(row,1)
End If
End If
Next
End Sub

Answer 2

This is the edit to what you started. I made the range dynamic, because I don't like making excel loop longer than it has to. That's my personal preference. The first block of code will copy over anything that isn't 0 or blank, and any negative numbers will be represented by their positive counterpart. That's at least how I understood your question.
Also, this code looks at data in Col N (like you have in your code) and copies the data to Col L. If you want A to B then simply change rng to = ws.Range("A2", ws.Cells(ws.Rows.Count, "A").End(xlUp)) and the myCell.Offset() to (0, 1).
Sub Verify()
Dim ws As Worksheet
Dim rng As Range
Set ws = ThisWorkbook.Sheets(1) 'good form to always define the sheet you're working on
Set rng = ws.Range("N2", ws.Cells(ws.Rows.Count, "N").End(xlUp)) 'dynamic range
For Each myCell In rng
If myCell.Value <> "" And myCell.Value <> 0 Then 'If the cell isn't 0 or ""
If myCell.Value < 0 Then 'Then if it's negative, make it positive and copy it over
myCell.Offset(0, -2).Value = myCell.Value * -1
Else: myCell.Offset(0, -2).Value = myCell.Value 'otherwise copy the value over
End If
End If
Next myCell
End Sub
If you only want to copy over values that are greater than 0, and ignore 0's, blanks, and negative values, then use this code:
Sub Verify()
Dim ws As Worksheet
Dim rng As Range
Set ws = ThisWorkbook.Sheets(1) 'good form to always define the sheet you're working on
Set rng = ws.Range("N2", ws.Cells(ws.Rows.Count, "N").End(xlUp)) 'dynamic range
For Each myCell In rng
If myCell.Value <> "" And myCell.Value > 0 Then 'If the cell is > 0 and not ""
myCell.Offset(0, -2).Value = myCell.Value 'copy the value over
End If
Next myCell
End Sub

Answer 3

If I understand your question correctly, you can "simplify" it to something like this:
Sub Verify()
[b2:b1000] = [if(iferror(-a2:a1000,),abs(a2:a1000),b2:b1000&"")]
End Sub
just replace a2:a1000 with your Column A range and b2:b1000 with the Column B range.