Something like this should get you started:
Sub myHighlighter()
Dim myWord As String
Dim rngStory As Word.Range
myWord = InputBox("Type word you want to find and highlight:")
For Each rngStory In ActiveDocument.StoryRanges
FindAndHighlight rngStory, myWord
Set rngStory = rngStory.NextStoryRange
Next
End Sub
Sub FindAndHighlight(ByVal rngStory As Word.Range, myWord As String)
Do Until (rngStory Is Nothing)
With rngStory.Find
.ClearFormatting
.Replacement.ClearFormatting
.Text = myWord
While .Execute
rngStory.HighlightColorIndex = wdBrightGreen
Wend
End With
Set rngStory = rngStory.NextStoryRange
Loop
End Sub
I have an addin that you can use it you like:
http://gregmaxey.mvps.org/Find_it_tool_bar.htm