Edit Length Based On Other Column

I have two columns, one with an account number (call it A) and another with a vendor id (call it B). I need the length of the number in column A to be truncated to 10 characters by just deleting any additional characters after 10. That should be based on whether or not the corresponding cell in column B equals the following number "147212336". Right now, my code edits the ENTIRE column A, not just the cell in the same row.

I know it's because I'm using a "FOR EACH CELL" argument but I don't what else would work.

Code:
Set acctlengthrange = Range("N2", Cells(LastRowB, "N"))
Set dplrange = Range("P2", Cells(LastRowB, "P"))
With dplrange
If cell.Value = "147212336" Then
For Each cell In acctlengthrange
cell.Value = Left(cell.Value, 10)
Next
End If
Next