In MCEdit, is there a way to manually specify the coordinates of a region?

Title pretty much says it all. I'm trying to clear out a large region in the Nether to build a gold farm, and I'm really struggling with the GUI, I know exactly the regions I want to specify (x/y/z) and the filters I need to run, but with all the crap in the nether, it's extremely difficult to get the GUI to select the entire box. Is there a way I can just specify the X/Y/Z coordinate ranges of the region I wish to filter?