Example: Let's say I have a 12 level fighter/barb with a BAB of 12....so I get three attacks. But I want to split them. I don't necessary want all three to go to the enemy I click on. I've tried doing the "single attack" option but that just gives me 1 total attack for the round! ugggh! The reason this is important is because I have fighters with high str using reach weapons. When I cast enlarge person on them I have my pick of enemies. Killing 1 weak enemy could allow me free attacks via cleave and great cleave. But it seems that all I can do is pick 1 enemy and let my fighters go all out on them with all their attacks. It's been years since I played this game but I feel like there was a way to control each individual attack back when I played. Maybe I'm mistaken. Any advice/answers will be greatly appreciated.
Select "full attack" from the radial menu, which will give you your 3 attacks. Then use your mouse and left click on whatever opponent you want to attack.
Also don't forget to use the 5' step at any point during or after the full attack to full effect. Step closer if you run out of targets within range if you have attacks remaining, or step away from targets to get a free AoO on enemies moving through your threat area between the end of your current turn and the start of your next turn. This second option also prevents most enemies from making multiple attacks against you as they 'move' to get in range rather than '5' step' to get in range thus denying themselves the full attack option, it's a bit of an 'AI limitation exploit' to use this tactic, but then ToEE isn't always easy.