It will all depend on how exactly the spindles are lowered but I would presume they are just air solenoids and just require one output each to lower and spring return.
So you would have to alter the m6start.m1s macro to operate the required output for the tool being called and also turn off the ouput for the current tool.
In addition your macro would also have to alter the X ? axis offset depending on which tool. How you do the offset would depend on how your code is produced, but likely a G52 temporary offset would work.
Hood