try using a copy sop. In the left branch you just put the line that will be duplicated. On the right branch you should plug the points where the line will be placed. This way you'll have identical copies of the first line. The easiest way you can modify the scale is changing the pscale attribute in the right branch whit something like this:
if(@ptnum%5==0){ f@pscale=2; } else{ f@pscale=1; }