This works via updating a .obj file. I'm sure puzzle dude could whiz through a mesh map and do the same thing in real time.
It woks in two steps;
First you call ScaleInit() which returns a model structure (This loads in the cube.obj file and does a little setup)
Then you call ScaleCube(filename, model, x_scale, y_scale, z_scale)
ScaleCube will create a .obj file named filename (you need to add .obj) scaled by x_scale, y_scale, z_scale. model is the structure returned from ScaleInit()
Note that if you don't use the "raw:" prefix it will place the file in C:\Users\your_name\AppData\Local\AGKApps\your_app\media
It's a bit of a hack and could be a lot more efficient but i figured seeing as it's a map editor you could just copy over the files to your game
Anyway. Hope it works for you
Note the cube in the image has been scaled x=2, y=3, z=4