Point to Multipoint

I have 3 arduinos. one of them should send signal the other two arduino but i should not use broadcast mode. I am using xbees in AT mode. How can i communicate with each other at unicast mode?I know I should change DL DH parameter. Should i use AT commands to do that? Is there any trick to do easy way? I cannot trust reliability of AT commands.

Yes you would need to enter command mode, change the DL/DH values and Exit command mode. Then send the data.

However, most arduino libraries that exits for the XBee use API mode instead. This keeps you from having to change the value via AT command mode.