1. Download Bot Events
2. Enter these events in a vehicle/zombie spawn with the vehicle set as "Standard Bot":
0 | 0 | onBotSpawn | Self | fireRelay
1 | 500 | onRelay | Self | fireRelay
2 | 0 | onRelay | Self | setBotAim [I think] | NearestPlayer
3 | 0 | onRelay | Self | BotAttack | FireWeapon
Hope that helps.