As I have already taken pains to express, the find whole word option is disregarded when using symbols and such in the find string. You have to do it in steps:
Code:
Sub InSteps()
Dim oRng As Range
Set oRng = ActiveDocument.Range
With oRng.Find
.Text = "Ë_do"
.Replacement.Text = "Aardvark"
.Execute Replace:=wdReplaceAll
Set oRng = ActiveDocument.Range
.Text = "Aardvark"
.Replacement.Text = "Whatever you want to replace with"
.MatchWholeWord = True
.Execute Replace:=wdReplaceAll
Set oRng = ActiveDocument.Range
.Text = "Aardvark"
.Replacement.Text = "Ë_do"
.MatchWholeWord = False
.Execute Replace:=wdReplaceAll
End With
End Sub