how to define my 3rd visible cell as variable in column B - excel

Question

I would like to define the variable of the 3rd visible cell in my filtered column B.
The position of my 3rd visible cell can change according to the value selected in my filter.
In my example, the 3rd cell is B16, but it is not always this value. If I manage to define the variable of my 3rd visible cell in column B, I would be able to change B16 in my VBA code by this variable.
Sub jfdjdgfjg()
Dim LastRow As Long
LastRow = ActiveSheet.Range("B" & Rows.Count).End(xlUp).Row
ActiveCell.Formula = "= SUM(B16:B" & LastRow & ")" 'Sum until lastrow
End Sub

Answer 1

This is one method
Option Explicit
Sub thirdviscell()
Dim LRow As Long, i As Long, counter As Long
Dim thirdcell As Range
With ThisWorkbook.Sheets(1)
LRow = .Cells(.Rows.Count, "A").End(xlUp).Row
For i = 2 To LRow 'assuming a header row not to be counted
If .Rows(i).EntireRow.Hidden = False Then counter = counter + 1
If counter = 3 Then
Set thirdcell = .Cells(i, "B")
Exit For
End If
Next i
End With
MsgBox "The third visible cell's address is " & thirdcell.Address(0,0), vbInformation
End Sub

Answer 2

You can loop over the visible cells and count them like this:
Option Explicit
Private Sub Example()
MsgBox GetFilteredRowNumber(ActiveSheet.Range("B:B"), 3)
End Sub
Private Function GetFilteredRowNumber(ByRef r As Range, ByRef num As Long) As Long
Dim aCell As Range, i As Long
GetFilteredRowNumber = 0
For Each aCell In Intersect(r.Parent.UsedRange, r.SpecialCells(xlCellTypeVisible)).Cells
i = i + 1
If i = num Then
GetFilteredRowNumber = aCell.Row
Exit For
End If
Next aCell
End Function