You could use a fairly simple Find/Replace macro assigned to a keyboard shortcut. For example:
Code:
Sub Demo()
Application.ScreenUpdating = False
With Selection.Range
With .Find
.ClearFormatting
.Replacement.ClearFormatting
.Text = "([0-9]) "
.Replacement.Text = "\1^s"
.Forward = True
.Wrap = wdFindStop
.Format = False
.MatchWildcards = True
.Execute Replace:=wdReplaceAll
End With
End With
Application.ScreenUpdating = True
End Sub
Simply select the range to process - if you don't select anything, everything from the insertion point to the end of the document will be processed.
Making an autocorrect option for this would probably cause more problems than it's worth - even you most likely don't want a non-breaking space to replace the ordinary space after
every number or even most numbers in a given document.