I have a model that printed about 80% through, and then when I tried to pause to add resin, it popped off the platform. It looks great, so I'd like to try and print the rest of it as a second piece (separately) so I can glue them together. 

I feel confident I have the correct slice where the print failed. Is there a way in Chitubox to export the .ctb so that the printer will start at the later slice (not at the zero slice) or do I have to estimate the position and crop the original .STL, and then import it into chitubox for slicing?

I'm using sn Elegoo Mars II (NOT Pro)