you first need to go through the list of these pio's:
ForEachObject();
Then when you have retrieved the handle to the object:
SetRField(obj_handle,'Name of Pio','Draw Beam',false or true);
You can also look in the online reference instead of the built in one, there are some tips with each command etc.
http://www.nemetschek.net/support/custom/vscript/reference/default.asp