Cpying Unique entries to new spreadsheet

[gavster]

I'm trying to write a macro to use as an auto-update feature for a spreadsheet.

I currently use Data validation on an input cell to allow the user to select from a list of product types.

I'd like the update to affect this list, so new product types are always available to the user.

However, the list of product types is in another spreadsheet and contains numerous repetitions.

I've managed to get the following code together based on what I've used before and what I've found searching so far, but it seems to have a bug in it as it wont always work. I also need the original copying of the list to be done to either the new spreadsheet of a different page in the original spreadsheet, but every time I try this it causes an object error.

Sub Macro3()
'
' Macro3 Macro
' Macro recorded 05/12/2008 by Information Technology
'
    Workbooks.Open Filename:= _
        "T:\SST\CCD\Engineering\Backthin_data\Photolith\MASK_DETAILS.xls"
   Sheets("Mask List").Range("f4:f2000").AdvancedFilter Action:=xlFilterCopy, _
        CriteriaRange:=Range("a1:a3"), CopyToRange:=Range("E1:E2000"), Unique:= _
        True
    Selection.Sort Key1:=Range("E1:e2000"), Order1:=xlAscending, Header:=xlNo, _
        OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom
        Columns("E:E").Select
        Selection.Copy
      Windows("MASK_DETAILS.xls").Activate
    ActiveWindow.Close
    Windows("Dry_etcher_log_B.xls").Activate
    Sheets("Calc Sheet").Select
    Columns("M:M").Select
    ActiveSheet.Paste
 End Sub 

Could someone kindly point me in the correct direction.

Thank,
Gavin.