Does anyone know how to set the text in a display dimension? I cant get it to work

Dim swApp As SldWorks.SldWorks
Dim moddoc As SldWorks.IModelDoc2
Dim selmgr As SldWorks.ISelectionMgr
Dim comp As SldWorks.Component2
Dim test As Object
Dim testDim As SldWorks.IDisplayDimension

Dim mark As Long
Dim complete As Boolean

Sub main()
   
    Set swApp = Application.SldWorks
    Set moddoc = swApp.ActiveDoc
    Set selmgr = moddoc.SelectionManager
 
    For ii = 1 To selmgr.GetSelectedObjectCount
        Dim partinfo As String
        Dim Part As SldWorks.ModelDoc2
       
        MsgBox selmgr.GetSelectedObjectType3(ii, mark)
        If selmgr.GetSelectedObjectType3(ii, mark) = 14 Then '14=dimension
            Set testDim = selmgr.GetSelectedObject6(ii, mark)
            MsgBox testDim.ShowDimensionValue
            MsgBox "Get dimension " & Round(testDim.GetDimension2(1).Value, 5)
            MsgBox "Precision: " & testDim.GetPrimaryPrecision
            MsgBox "Precision2: " & testDim.GetPrimaryPrecision2
            MsgBox "Alternate: " & testDim.GetAlternatePrecision
            MsgBox "Gettext: " & testDim.GetText(1)
            MsgBox "Use dual dim: " & testDim.GetUseDocDual
            MsgBox "Linked text: " & testDim.GetLinkedText
            MsgBox "Use doc precision" & testDim.GetUseDocPrecision
            complete = testDim.SetText(1, "nej")
            complete = moddoc.GraphicsRedraw2()
           
           
        End If

    Next

End Sub