Generating Structures With Procedures

I need to make a block that generates structures when certain conditions are met. I've seen peolple talk about procedures that load and generate specific structures, but i couldn't find a single post explaining how it is done. The only thing i can find in the procedure menu that is even close to structure generation is "place block at [x] [y] [z]", but i'd like to generate a structure based on a structure file, not write instructions to build the structure down block by block.

Is there a way to do that currently? (And yes, i know how to save and import structures)