How to apply horizontal load at the center of gravity of equipment?

Hi,

I want to apply horizontal load at the center of gravity of equipment (due to wind and acceleration), however only the base or foot print of the equipment is modeled in staadpro. Are there any options to do this in Staadpro other than applying to the base i) a force in horizontal direction and ii) a couple force in vertical direction (to represent the moment)?

Thanks

Yan