Yes, it is easy to do. go to the ... O botten, not sure what menu it is off hand. open a macro butten and drag your 2 weapons in to it. make sure that one is set to Primary and one is set to Secondary. You can do this with other equipment slots, but the only slot of can change in combat is weapons and ranged.
O, Edit: Make sure you drag the new macro to a hot bate some where.