You’ll have to manually edit the gcode to start halfway through.
You can use a visualizer like this one to help you know where you were.
Once you know, i always go back to a previous retract move and remove everything, aside from the header, before that point.
Are you familiar with gcode?
Another option would be tojust speed up the feedrate 200% until you get close.
Last, if it works for your project, you could generate new code with the previously carved areas covered.