Maxscript acces to Wall

Hello to all. Recently i have been doing a script that needs to get acces to the AEC wall object. I need to get acces to the 'pick spline' option in keyboard entry option from the modify panel to assign a previously created spline , but i have no idea on how to get it cause it doesn't seem to have a straightforward way to get into it. I can use the 'startObjectCreation Wall' to start creting the wall, but after that, i don't know where find a method to attach the spline right into it.

Any ideas about that one?..

Thanks in advance!!!