Crane Moving Load - including lateral load

I have a two-span underhung crane beam that i wanted to design using Staad. I wanted to use the Moving load command to model the load as it moves across the frames. I've been able to model the downward force of the crane, however i have been unable to model the 20% lateral load on these memebers .

Is there a way to change the direction of load in the moving load command?

Thank you.