Macro for conditional formatting bottom border

hi Graig, sort of that

Sub test()
    
Dim rng As Range, sh As Worksheet, breaks_count as long
    
On Error Resume Next
    
Set sh = ActiveSheet
    
breaks_count = sh.HPageBreaks.Count

For i = 1 To breaks_count
    If rng Is Nothing Then Set rng = sh.Cells(sh.HPageBreaks(i).Location.Row - 1, 1) Else Set rng = Union(sh.Cells(sh.HPageBreaks(i).Location.Row - 1, 1), rng)
Next
    
If Not rng Is Nothing Then rng.Borders(xlEdgeBottom).Weight = xlThin
    
End Sub