You could use a macro like:
Code:
Sub Demo()
Dim i As Long, StrFnd As String, StrRep As String
StrFnd = "A,E,I,O,U"
StrRep = "á,é,í,ó,ú"
With ActiveDocument.Content.Find
.ClearFormatting
.Replacement.ClearFormatting
.Forward = True
.Wrap = wdFindContinue
.Format = False
.MatchWildcards = True
For i = 0 To UBound(Split(StrFnd, ","))
.Text = "(<[A-Za-z]@)" & Split(StrFnd, ",")(i) & "(*>)"
.Replacement.Text = "\1" & Split(StrRep, ",")(i) & "\2" .Execute Replace:=wdReplaceAll
.Execute Replace:=wdReplaceAll
Next
End With
End Sub
The second '.Execute Replace:=wdReplaceAll' is to allow for the possibility that a given word might contain two of the same character to be converted.
For a manual
wildcard Find/Replace, you'd use expressions like:
Find = (<[A-Za-z]@)A(*>)
Replace = \1á\2