Last Page depends upon how many rows are included in one page, as you can preview and adjust by means of "View - PageBreak Preview" tool.
A very rudimentary method could be (after having defined a Print_Area using "File - Print_Area - Set Print_Area" with some spare rows for footer):
Private Sub Worksheet_Activate()
b$= ActiveSheet.PageSetup.PrintArea
k=Range(b$).Rows.Count \ 52 ' assuming 52 rows per page
[A1].Offset(52*k +15, 1)="THIS IS MY FOOTER !" ' 15 rows
End Sub
Hope it helps
_LF