I want to be able to enter a time, using "." instead of ":", so that
when I enter the number, then press "Enter", the number changes from,
say, 13.27.33 to 13:27:33. But I am having to reselect the cell to get
it to change. What is wrong with my code?

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Selection.Replace What:=".", Replacement:=":", LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=False, SearchFormat:=False,
_
ReplaceFormat:=False
Selection.NumberFormat = "h:mm:ss"
End Sub

Thanks,

Tonso