I have already provided you the answer twice. If you can't post functional code, why should anyone else. The code I have given you acted on footnote 1. If you want an "a" after all footnotes you can use:
Code:
Sub ScratchMacro3()
'A basic Word Macro coded by Gregory K. Maxey
Dim ftNote As Footnote
Dim supLetter As String
supLetter = "a"
For Each ftNote In ActiveDocument.Footnotes
With ftNote
.Range.Characters.First.Previous.Delete
.Range = supLetter & " " & .Range
.Range.Characters.First.Font.Superscript = True
End With
Next
lbl_Exit:
Exit Sub
End Sub