You can do this with a regular search and replace. Recording this as a macro would end up something similar to this
Code:
Sub HiLiteCourses()
Options.DefaultHighlightColorIndex = wdYellow
With Selection.Find
.ClearFormatting
.Replacement.ClearFormatting
.Replacement.Highlight = True
.Replacement.Font.Color = wdColorRed
.Text = "course"
.Replacement.Text = ""
.Forward = True
.Wrap = wdFindContinue
.Format = True
.MatchCase = False
.MatchWholeWord = False
.MatchWildcards = False
.MatchSoundsLike = False
.MatchAllWordForms = True
.Execute Replace:=wdReplaceAll
End With
End Sub