In autoCAD2004,
 
suppose 3 parallel lines are crossed by a 4th line( may be circle or arc). I want to break only 3 parallel lines ( not 4th one) at its intersection points. How to perform this in autoCAD2004 in easy way. I have lisp "breakall" which breaks 4th line also which is not my requirement. 
 
This is very useful for me to show hidden parts on drawings. I can break lines at all intersection points and convert hindden parts into hidden lines (dotted). But not the outer part lines.   
AND how these lines can be joined, if broken?