How do you load a unit mesh in a certain 9pose? I need this to properly place the hp_pilot on my speeder model. I'd like to import the 9pose of the Endor speederbike to use as a reference.

Are you asking what to put in the odf or where to put the hp_active in the model?
For the odf is is just these set of lines

PilotPosition = "hp_active"
Pilot9Pose = "speederbike_9pose"
AnimationName = "imp_hover_speederbike"
FinAnimation = "imp_speederbike_9pose"

If you are asking where about where to put the hp then it is approximately where you think he would sit then a bit of playing to get it correct

Perhaps I phrased that oddly. I want to import the speederbike 9pose into XSI, so I have a character in that pose, so I can use that as a reference to model things.

thats not possible

The only thing that would do that would come close would be the human_speederbke_9pose.msh and that would be at frame 0 which is moving forward turning left. If you want a reference as to where things should line up you'd be better off importing the speederbike msh itself and make sure things like the handlebars, pedals and set line up with it on your model.
Oh as a side note, hp_active for the speederbike is at 0,0,0 so basically at and primitive or null creation point so you don't have to worry about lining it up too much.