parametric wall hole? It depends on what you mean by that. You can of course make holes in a PARAM-O object of any shape or dimensions you want. And you could control an array of PARAM-O objects with PARAM-O functionality for cutting those holes. SEO may be a part of the solution. Parametirc? That also depends some on what you mean by that. Perhaps you could pick up some ideas about how you want to use PARAM-O to tryout different arrays of openings of different sizes by downloading this sample object?
" Window panel
We used the Random Series node to create the holes in the window panel randomly. Each and every hole is different. Edit the subtype of the object using the GDL editor. In this example, the subtype is Window. Access this object using the Window Tool."