Written by Joe Cocuzzo, Senior VP of Report Writing Services - iatricSystems
%Z.graphics can be used to print horizontal lines of desired thickness and length anywhere on the page.
A loop and a set of calls to Z.graphics could do what you want.
If you don't have an Iatric mousepad, go here: http://www.iatric.com/information/z-programs.asp for details on the arguments to be used.