How to set the velosity on offboard mode.I mean not by Vx Vy Vz vector Composition

I am not a english speaker, I am trying to make myself clear.
I mean with Vx Vy Vz vector Composition,I will get a Composed V with specific direction. I want a V that can travel in any direction on OFFBOARD MODE.
I get that MISSION ITEM.COMMAND 178 which is DO_CHANGE_SPEED can set the travelling speed.Can i make this CHANGE on OFFBOARD MODE? THANKS