perhaps try somethink like this:
Code:
phent_enable(me, 0);

phcon_remove(hingeID); 

hingeID= phcon_add( PH_HINGE, box_2,box_1);
phcon_setparams1(hingeID, **i_want_to_change_this_vector***,vector(0,0,1), nullvector);
phcon_setparams2(hingeID,  vector (-360, 360, 0) , nullvector, nullvector); 

phent_enable(me, 1);