Did you try what I suggested? It should give you the VBA code that you require.Yes, this is part of a bigger VBA tune up of a spreadsheet. Would really like this code to work.
You can actually get the VBA code for that Conditional Formatting by turning on the Macro Recorder, and recording yourself applying the Conditional Formatting manually.
Sub AddBorder()
Dim Rng As Range
With Range("C1:C" & Rows.Count - 1)
.AutoFilter 1, ">=" & 5000000
Set Rng = .Offset(1).SpecialCells(xlVisible)(1)
Rng.Offset(-1, -1).Resize(, 10).Borders(xlEdgeBottom).Weight = xlMedium
.AutoFilter
End With
End Sub