On my DX8 I had set up a slight up elevator on a switch. Hand launch and flick the switch for flight trim. I am clueless on how to do this on my 18. Don't remember what I did on the 8.
I use the flaps menu for that. Just assign the desired elevator deflection to the launch switch position, leaving the flaps at 0. You can also program the speed of the change. If you have no flaps, never mind. Just pretend you have them and assign them to an unused channel. I find this the most natural and elegant way.