[Scripting Question] Add safari-style ball command to normal command menu

My game has Poke Balls as the only usable in-battle items. I posted on here a while ago asking for potential ways to make the bag menu of EBDX automatically direct to the Poke Balls section, but I have since realized that it would be much simpler to just have one type of Poke Ball available in my game, increase catch rates slightly, and replace the bag command with one that automatically throws a Poke Ball, as with the Safari Zone. How can this be done?

I've poked around a fair bit on my own, and Safari Zone battles seem to have their own structure somewhat detached from the rest of the battle system. As far as I can tell, the best way to accomplish my goal would be by rewriting the pbItemMenu function in Battle_Phase_Command to return a result as though the player had selected a Poke Ball, but I'm stuck figuring out how exactly to achieve that. Any help or advice would be much appreciated!