Ooops, I may have posted some crappy code before. If you're trying to just underline that word, maybe just the use find and replace to underline it? That should only underline that title:
Code:
With Selection.Find
.Text = " Product Specifications"
.Replacement.Text = " Product Specifications"
.Replacement.Font.Underline = True
.Forward = True
.Wrap = wdFindContinue
.Format = True
.MatchCase = False
.MatchWholeWord = False
.MatchWildcards = False
.MatchSoundsLike = False
.MatchAllWordForms = False
End With
Selection.Find.Execute Replace:=wdReplaceAll
Hope this helps...