shorting between patch and ground

1.Try to create an edge on the patch on where you want to have the shorting wall. You can use EDIT->DIVIDE POLYGON command or ADV EDIT->SEPARATE POLYGONS command for it. 2. Then, select the edge on the patch and use EDIT->ADD VIA ON EDGES or ADV EDIT->BUILD VIA CONNECTIONS ON EDGES to build the via. The 2nd command has option to build a v-localized port. For IE3D V14 to be released, you can just enter a vertical polygon and use ADV EDIT->CONNECTION->ADJUST GEOMETRY FOR CONNECTIONS and let MGRID to build the connection on edge for you.

you can make a wall made out of vias.
It is not going to be solid but is a good
aproximation.