LASTINCOLUMN

LASTINCOLUMN(rgeInput)
Returns the last cell that contains data in a particular column.

REMARKS
Public Function LASTINCOLUMN( _

Public Function LASTINCOLUMN( _ 
         rngInput As Range) _ 
         As Variant 

Dim WorkRange As Range 
Dim i As Integer 
Dim CellCount As Integer 

   Application.Volatile 
   Set WorkRange = rngInput.Columns(1).EntireColumn 
   Set WorkRange = Intersect(WorkRange.Parent.UsedRange, WorkRange) 
   CellCount = WorkRange.Count 
   For i = CellCount To 1 Step -1 
       If Not IsEmpty(WorkRange(i)) Then 
           LASTINCOLUMN = WorkRange(i).Value 
           Exit Function 
       End If 
   Next i 
End Function 

For instructions on how to add this function to a workbook refer to the page under Inserting Functions