for the /melee it falls under stickcmd. You could go to your INI and under [Melee] change or add the line stickcmd=stick 10 front loose uw moveback
or something to that affect. front positions you in front, you could instead put back to be behind the mob. 10 is the distance from the target. loose means to be roughly in front of the target instead of being exactly in the front. uw meaning underwater (look up and down depending on if the target is above or below you (so you can see them when on land, and follow underwater/levitating if swimming/levitating) moveback....it moves you back. If doing this while in game then type /melee load. If out of game then you should just need to load into eq.