You can use something like:
dom321 --allai --superhost --scoredump --postexec /home/dom/dominions3/savescores.sh mygame
Where savescores.sh just copies the scores.html to a unique filename,
Code:
#!/bin/bash
cp /home/dom/dominions3/savedgames/mygame/scores.html /home/dom/dominions3/savedgames/mygame/scores.$(date +%s).html
Try it with the Dawn of Dominions map.