The answer brought up by @Lopsided wont work, if there are other hidden cells after the nth entry. They would then be added to the absolute position.
This'll work, you have to change n by yourself in the script. Changing that shouldn't be to hard. If you have any questions regarding that, feel free to ask. (;
Sub absoluteRowID()
Dim RowCount, hiddenRows As Integer
'relative position n
n = 5
i = 0
Do While i < n
i = i + 1
If ThisWorkbook.Sheets(1).Rows(i).EntireRow.Hidden Then
'if there is a hidden row, position is incremented
n = n + 1
End If
'if there is no hidden row, nothing happens
Loop
MsgBox (i)
End Sub
HTH