Macro: Remove Duplicate before Pasting Text (on selected cells)

Hi all members,

Using this macro, when you select several cells (using ctrl+click) , for example cell B12 + C13 + D16 (then run the macro), it will will copy values of cell I12, I13, I16. In otherword, no matter which cells you selected, it will always copy cell of column "I" (under that same row the cell was selected)

(originally from a guy call Karan and modified by Alphafrog in this thread)

Sub CopySelectedCells()
    Dim str As String, rangeRow As Range
    For Each rangeRow In Selection.Rows
        str = str & Cells(rangeRow.Row, "I").Value
        str = str & ","
    Next
    str = Left(str, Len(str) - 1) & vbCrLf
    
    With New MSForms.DataObject 'Early binding (requires reference to MSForms 2.0 Obect library)
    'Late binding (does not require reference)
    'With CreateObject("new:{1C3B4210-F441-11CE-B9EA-00AA006B1A69}")
        .SetText str
        .PutInClipboard
    End With
End Sub

Now the problem is, sometime the selected cells contain same values (duplicate)

Can someone help modify this macro so that it will copy and remove duplicates value, if any. (the remove process should be done before pasting the data into other media, such as notepad)

p.s: my knowledge in VB is way below basic

Dear Mike, tons and tons of thanks to you....it works just like i wish for.

this is the final looks of the macro that i implement (see the blue comments)

Sub CopySelectedCells()
 Dim str As String, rangeRow As Range
 With CreateObject("scripting.dictionary")
    For Each rangeRow In Selection.Rows
        If Trim$(Cells(rangeRow.Row, "I").Value) <> vbNullString Then
            If Not .Exists(Trim$(Cells(rangeRow.Row, "I").Value)) Then
                .Item(Trim$(Cells(rangeRow.Row, "I").Value)) = Trim$(Cells(rangeRow.Row, "I").Value)
            End If
        End If
    Next
    str = Join$(.Items, ",")
 End With
''MsgBox str ( instead of poping up the msgbox, i prefer the data in the clipboard, so i changed back to the original )
    With New MSForms.DataObject
    .SetText str
    .PutInClipboard
End Sub

many thanks again mike

regards,
rampal

i prefer the data be putted in the clipboard (instead of in a pop-up msgbox) so it can be pasted into word or notepad
that's why i changed back to the original