Sub SpacesInThousands()
' Paul Beverley - Version 29.11.16
' Changes four-figure numbers from comma to space.

' Start from the top of the document
Selection.HomeKey Unit:=wdStory

With Selection.Find
  .ClearFormatting
  .Replacement.ClearFormatting
  .Text = "^#,^#^#^#"
  .Wrap = wdFindStop
  .Replacement.Text = ""
  .Forward = True
  .MatchWildcards = False
  .Execute
End With


Do While Selection.Find.Found = True
' Note where the end of the found item is
  endNow = Selection.End

' Make your required change
  oldText = Selection.Text
  newText = Replace(oldText, ",", " ")
  
' or if you prefer a fixed space?
' newText = Replace(oldText, ",", ChrW(160))
  
' Type in the replacement text
  Selection.TypeText newText
  
  ' Be sure you're past the previous occurrence
  Selection.End = endNow
  Selection.Collapse wdCollapseEnd

' Go and find the next occurrence (if there is one)
  Selection.Find.Execute
Loop
End Sub