A family of Microsoft word processing software products for creating web, email, and print documents.
Doug has very kindly provided some modified code that may work better for your purposes. I would modify it as follows, so it doesn't underline a comma that follows Exhibit A:
Sub Demo2()
With Selection
.HomeKey wdStory
.Find.ClearFormatting
With .Find
Do While .Execute(FindText:="Exhibit ^?", MatchWildcards:=False, MatchWholeWord:=True, Forward:=True, Wrap:=wdFindStop) = True
With Selection
.MoveEndUntil Cset:=" " & ","
.Font.Underline = wdUnderlineSingle
.Collapse wdCollapseEnd
End With
Loop
End With
End With
End Sub