DateAdd accepts a wide variety of inputs and outputs in the correct format.
ThisLine = "Tuesday, September 04, 2012 2:02 PM"
i = InStr(ThisLine, ",") ' get rid of the leading day
If i > 0 Then
TempResult = Trim(Right$(ThisLine, Len(ThisLine) - i))
end if
TempResult = DateAdd("s", 0, TempResult)