[XeTeX] Font question

[Jonas Wellendorf]

This is not strictly a xetex related question or problem, but a problem 
I have encountered while using xetex.
In my documents I need the character ǫ (hooked o). In regular latex I 
type \textpolhook{o} to get this character. In xetex using a font such 
as Gentium I simply enter alt+j and then o on my Norwegian keyboard. 
But how do I get the same character while using say Hoefler Text?

Thank you,
Jonas
-- 
Jonas Wellendorf
Doctoral fellow
Centre for Medieval Studies
University of Bergen, Norway

E-mail: Jonas.Wellendorf at cms.uib.no
Phone: (+47) 55 58 80 93