Richtextbox : highlight entire line based on found word

[Ultrawhack]

In a richtextbox, how can I highlight the entire line where a given word is found. eg "fox"

Thanks for any help.

 

[Xancholy]

Richtextbox : highlight till end of line if text found

A richtextbox can only highlight till the end of a line.

But if you fill the line till the right edge of the richtextbox with blank spaces then it will highlight till the right margin of the richtextbox.

To mimic the attached image of this control,

If the word "Verse" is found at the start of a line...
How can I fill the rest of the line with blank spaces till the edge of the richtextbox..???
and then highlight the entire line ?