Hello Houdini People

I am almost done with the project, but I just wonder if it is possible to do add the parameters without touching edit operator type properties window. For my hda, it goes through boxes one by one (For each loop)and meshes(wall, ceiling, etc.) is created based on the spawn point and normal on the boxes. The only problem that I have is that all the boxes get same meshes as other boxes and I want to put different meshes on each boxes. Is there a way to add parameters (at least file geometry parameter) on the different meshes (different attributes) or is there an alternative way to put the meshes with VEX?