Not 100% sure what you mean by "line splitter". Are you asking for putting a line between 2 menu items? If so, you could hard code some CSS to do that....
<li><a href="">Some menu item before split</a></li>
<li><a href="">Some items after split</a></li>
then in CSS something like:
Of course, this is only one method. There are other ways to make lines.