Removing duplicates within a cell

I can't find a way to remove duplicate values inside a same cell in Excel. For example, in A1, I have:

DOG DOG DOG

I want to have only DOG.

Actual code:

Sub test()
for i = 14 to 16
  transNumb= commRead(i, 23, 4)
next

If transNumb <> "    " and transNumb <> "F PA" then
        transNumbAcum = transNumbAcum + " " + transNumb
End if

Set exlTest = objExcel.Workbooks.Open(strPathExc)
objExcel.Application.Visible = True
exlTest.Sheets("ACCOUNT_CODE Day").Activate 
exlTest.Sheets("ACCOUNT_CODE Day").Cells(37, 4).Value = +transNumbAcum
exlTest.Close xlSaveChanges

objExcel.Quit
End sub

Code output: This will result certain values in the Excel cell (37, 4), such as:

2000 3000 0300 0300 2000

I am lost as to how to delete the repeated values in the cell.

EDIT:

I have these values in my cell A46: 2000 3000 4000 5000 3000 2000

Code I'm trying (doesn't seem to work)

Set d = CreateObject("Scripting.Dictionary")
            a = Split(objExcel.Sheets("ACCOUNT_CODE Day").Range("A46"), " ")

            For i = 0 To UBound(a)
            If Not d.Exists(a(i)) Then d.Add a(i), ""
            Next

            'Now your Dictionary should have unique values from your cell and you can recombine them:
            Set exlTest = objExcel.Workbooks.Open(strPathExc)
            objExcel.Application.Visible = True
            exlTest.Sheets("ACCOUNT_CODE Day").Activate 
            'exlTest.Sheets("ACCOUNT_CODE Day").Cells(37, 4).Value = +transNumbAcum
            'exlTest.Close xlSaveChanges
            'objExcel.Quit  

            objExcel.Sheets("ACCOUNT_CODE Day").Range("A46") = Join(d.Keys, " ")
            exlTest.Close xlSaveChanges

via Chebli Mohamed