'Lines' in Word are a vague concept.
Paul's code highlights from the word to the next paragraph mark, so if the paragraph is more than one displayed 'line' more than one 'line' will be highlighted.
If the 'lines' are terminated with a manual line break (Shift+Enter) or copied from this forum you may do better with
Code:
.Text = "Ken:[!^13^11]{1,}"
Note that the text is case sensitive.