Unfortunately, I rarely work in Excel and I'm not a programmer, so I can suggest a Word code to illustrate using a range:
Code:
Sub Replace_Digits_With_Wds()
Dim oRng As range
Application.ScreenUpdating = False
Set oRng = ActiveDocument.range
With oRng.Find
.ClearFormatting
.Replacement.ClearFormatting
.Forward = True
.Wrap = wdFindStop
.Format = True
.MatchWildcards = True
.text = Chr(9) & "1([!0-9])"
While .Execute
oRng.End = oRng.End - 1
oRng = Chr(9) & "-"
oRng.Font.ColorIndex = wdBrightGreen
oRng.Collapse wdCollapseEnd
Wend
Application.ScreenUpdating = True
Set oRng = Nothing
End With