How to add a orientation with a already given orientation?

I made a type of attack where it shoots out a beam first at a random orientation considering where the enemy is. Then after a while a model pivots to that area and does damage. The problem i am having is that my model's normal orientation is 90 degrees off and it declares it as a (0,0,0) so whenever i pivot the model to the beam the orientation is always 90 degrees off. How would i add a orientation to a original pivoted orientation to fix this?