Good use for broken rod. Add a reel seat and grip to tip end of broken rod. Use the drag of one reel to supply tension when winding on line. You can also use any suitable rod or pipe.
This is also a good way to add new line and correct amount of backing to reel.(A) First put new line on backwards (line first, then backing) till full. Wind all this onto reel B at other end. Take reel A off and put a third reel C on the opposite end and wind it all. Finally , put reel A back on and wind in line with drag set on opposite reel to apply tension. Takes 4 steps. You can also buy one of those clip on line counters if you want to measure how much line you are adding.
???My attachment option is NOT enabled, otherwise I would post a picture of my set up.