Sub NewWordReplacement1()
  Dim sCheckDoc As String
  Dim docRef As Document
  Dim docCurrent As Document
  Dim wrdRef As Object

sCheckDoc = "C:\Folder\Textfile.txt"
Set docCurrent = Selection.Document
Set docRef = Documents.Open(sCheckDoc)
docCurrent.Activate
Options.DefaultHighlightColorIndex = wdRed
With Selection.Find
    .ClearFormatting
    .Replacement.ClearFormatting
    .Replacement.Font.Bold = True
    .Forward = True
    .Format = True
    .MatchWholeWord = True
    .MatchCase = True
    .MatchWildcards = False
End With

For Each wrdRef In docRef.Words
    If Asc(Left(wrdRef, 1)) > 32 Then
        With Selection.Find
            .Wrap = wdFindContinue
            .Text = wrdRef
            .Execute Replace:=wdReplaceAll
            .Replacement.Highlight = True
        End With
    End If
Next wrdRef

docRef.Close
docCurrent.Activate
End Sub