If you downloaded something and it's in your Pose library, it's a MAT POSE file that needs to be applied to the appropriate figure or prop.  Since you said this is hair, look in the Figure library or the Hair library for the hair that you downloaded.  If it's a prop, you'll need to parent it to the character head.  If it's a hair figure, you'll need to conform it.  Once the hair is loaded and positioned, make sure it's selected and then go to the Pose folder and apply the MAT pose for it.

Hugz from Phoenix, USA

Victoria

Remember, sometimes the dragon wins. Correction: MOST times.