While not wanting to pour scorn on macro suggestion, you'll soon find it's rather inflexible. The following rendition will add parentheses to any selected alpha-numeric string:
Code:
Sub AddParens()
Application.ScreenUpdating = False
Dim i As Long
With Selection.Words.First
If (InStr(.Text, ")") > 0) Or (InStr(.Text, "(") > 0) Then Exit Sub
Do While .Characters.Last Like "[ ,.:;?!'" & Chr(7) & "-" & Chr(13) & "]"
.End = .End - 1
Loop
For i = Len(.Text) To 1 Step -1
With .Characters(i)
.InsertAfter ")"
.InsertBefore "("
End With
Next
End With
Application.ScreenUpdating = True
End Sub
Just don't try it with multi-character roman numerals...
If you assign the macro to a keyboard shortcut, it'll be ready for action without the need to go through the Developer tab, etc.